United States congressional apportionment is the process by which seats in the
United States House of RepresentativesThe United States House of Representatives is one of the two Houses of the United States Congress, the bicameral legislature which also includes the Senate.The composition and powers of the House are established in Article One of the Constitution...
are redistributed amongst the 50
statesA U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
following each
constitutionallyThe Constitution of the United States is the supreme law of the United States of America. It is the framework for the organization of the United States government and for the relationship of the federal government with the states, citizens, and all people within the United States.The first three...
mandated decennial
censusThe United States Census is a decennial census mandated by the United States Constitution. The population is enumerated every 10 years and the results are used to allocate Congressional seats , electoral votes, and government program funding. The United States Census Bureau The United States Census...
. Each state is
apportionedApportionment is the process of allocating political power among a set of principles . In most representative governments, political power has most recently been apportioned among constituencies based on population, but there is a long history of different approaches.The United States Constitution,...
a number of seats which approximately corresponds to its share of the aggregate population of the 50 states. However, every state is constitutionally guaranteed at least one seat.
Reapportionment
The number of seats in the House of Representatives is currently set to 435, and has been since 1913, except for a temporary increase to 437 after the admissions of Alaska and Hawaii. Though the actual reapportionment will normally occur in respect of a decennial census, the law that governs the total number of representatives and the method of apportionment to be carried into force at that time can be created prior to the census.
The decennial apportionment also determines the size of each state's representation in the U.S. Electoral College—that is, any state's number of electors equals the size of its total congressional delegation (i.e., House seat(s) plus Senate seats).
Federal law requires the
Clerk of the House of RepresentativesThe Clerk of the United States House of Representatives is an officer of the United States House of Representatives, whose primary duty is to act as the chief record-keeper for the House....
to notify each state government of its entitled number of seats no later than January 25 of the year immediately following the census. After seats have been reapportioned, each state determines the boundaries of
congressional districts—geographical areas within the state of approximately equal population—in a process called
redistrictingRedistricting is the process of drawing United States electoral district boundaries, often in response to population changes determined by the results of the decennial census. In 36 states, the state legislature has primary responsibility for creating a redistricting plan, in many cases subject to...
.
Any citizen of the State can challenge the constitutionality of the redistricting in their US Distrct court,
Title 28 United States Code, Section 2284 (a).
Because the deadline to report the results does not occur until the following January, the decennial census does not affect the elections that are held during that same year. For example, the electoral college apportionment during 2000 presidential election was still based on the 1990 census results.
Constitutional text
The subject of representation is addressed twice in the
U.S. ConstitutionThe Constitution of the United States is the supreme law of the United States of America. It is the framework for the organization of the United States government and for the relationship of the federal government with the states, citizens, and all people within the United States.The first three...
. Originally, the apportionment of
HouseThe United States House of Representatives is one of the two Houses of the United States Congress, the bicameral legislature which also includes the Senate.The composition and powers of the House are established in Article One of the Constitution...
seats was commanded by
Article IArticle One of the United States Constitution describes the powers of Congress, the legislative branch of the federal government. The Article establishes the powers of and limitations on the Congress, consisting of a House of Representatives composed of Representatives, with each state gaining or...
, Section 2, clause 3, which states:
Following the end of the
Civil WarThe American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...
, the above provision was superseded by Section 2 of the
Fourteenth AmendmentThe Fourteenth Amendment to the United States Constitution was adopted on July 9, 1868, as one of the Reconstruction Amendments.Its Citizenship Clause provides a broad definition of citizenship that overruled the Dred Scott v...
, which states:
Article I additionally provides that:
House size
Ratio of representation in the House, 1789–1913
| Years | Source | Constituents
per Rep. |
| 1789–1793 |
U.S. Const. |
30,000 |
| 1793–1803 |
1790 Census |
33,000 |
| 1803–1813 |
1800 Census |
33,000 |
| 1813–1823 |
1810 Census |
35,000 |
| 1823–1833 |
1820 Census |
40,000 |
| 1833–1843 |
1830 Census |
47,700 |
| 1843–1853 |
1840 Census |
70,680 |
| 1853–1863 |
1850 Census |
93,425 |
| 1863–1873 |
1860 Census |
127,381 |
| 1873–1883 |
1870 Census |
131,425 |
| 1883–1893 |
1880 Census |
151,912 |
| 1893–1903 |
1890 Census |
173,901 |
| 1903–1913 |
1900 Census |
194,182 |
| 1913–1923 |
1910 Census |
212,407 |
The size of the U.S. House of Representatives refers to total number of congressional districts (or seats) into which the land area of the United States proper has been divided. The number of voting representatives is currently set at 435. There are an additional five delegates to the House of Representatives. They represent the District of Columbia and the territories of
American SamoaAmerican Samoa is an unincorporated territory of the United States located in the South Pacific Ocean, southeast of the sovereign state of Samoa...
,
GuamGuam is an organized, unincorporated territory of the United States located in the western Pacific Ocean. It is one of five U.S. territories with an established civilian government. Guam is listed as one of 16 Non-Self-Governing Territories by the Special Committee on Decolonization of the United...
, the
Northern Mariana IslandsThe Northern Mariana Islands, officially the Commonwealth of the Northern Mariana Islands , is a commonwealth in political union with the United States, occupying a strategic region of the western Pacific Ocean. It consists of 15 islands about three-quarters of the way from Hawaii to the Philippines...
, which first elected a representative in 2008, and the U.S. Virgin Islands.
Puerto RicoPuerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...
also elects a
resident commissionerThe Resident Commissioner of Puerto Rico is a non-voting member of the United States House of Representatives elected by the voters of the Commonwealth of Puerto Rico every four years...
every four years.
Controversy and history
During the period that the current U.S. Constitution has been in effect, the number of citizens per congressional district has risen from an average of 33,000 in 1790 to almost 700,000 . Prior to the 20th century, the number of representatives increased every decade as more states joined the union, and the population increased. In 1911,
Public Law 62-5-Subsequent apportionment:For the first and only time, Congress failed to pass an apportionment act after the 1920 census. This left the allocations of the Act of 1911 in place until the 1930 census. The Reapportionment Act of 1929 established a method for reallocating seats among the states,...
raised the membership of the U.S. House to 433 with a provision to add one permanent seat each upon the admissions of
ArizonaArizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
and
New MexicoNew Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
as states. As provided, membership increased to 435 in 1912.
But in 1921, Congress failed to reapportion the House membership as required by the United States Constitution. This failure to reapportion may have been politically motivated, as the newly elected Republican majority may have feared the effect such a reapportionment would have on their future electoral prospects . Then in 1929 Congress (Republican control of both houses of congress and the presidency) passed the
Reapportionment Act of 1929The Reapportionment Act of 1929 was a combined census and reapportionment bill passed by the United States Congress that established a permanent method for apportioning a constant 435 seats in the U.S. House of Representatives according to each census...
which capped the size of the House at 435 (the then current number), but allowed temporary increases upon the admission of new states which were to be reverted upon the implementation of the immediate subsequent census.
In truth, the rules prohibiting legislative entrenchment would allow any subsequent legislature (after 1929) to increase or decrease the membership of the House of Representatives if such legislature so desired.
The current size of 435 seats means one member represents on average about 709,760 people; but exact representation per member varies by state. Three states –
WyomingWyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...
,
VermontVermont is a state in the New England region of the northeastern United States of America. The state ranks 43rd in land area, , and 45th in total area. Its population according to the 2010 census, 630,337, is the second smallest in the country, larger only than Wyoming. It is the only New England...
, and
North DakotaNorth Dakota is a state located in the Midwestern region of the United States of America, along the Canadian border. The state is bordered by Canada to the north, Minnesota to the east, South Dakota to the south and Montana to the west. North Dakota is the 19th-largest state by area in the U.S....
– have populations smaller than the average for a single district.
The "ideal" number of members has been a contentious issue since the country's founding.
George WashingtonGeorge Washington was the dominant military and political leader of the new United States of America from 1775 to 1799. He led the American victory over Great Britain in the American Revolutionary War as commander-in-chief of the Continental Army from 1775 to 1783, and presided over the writing of...
agreed that the original representation proposed during the
Constitutional ConventionThe Constitutional Convention took place from May 14 to September 17, 1787, in Philadelphia, Pennsylvania, to address problems in governing the United States of America, which had been operating under the Articles of Confederation following independence from...
(one representative for every 40,000) was inadequate and supported an alteration to reduce that number to 30,000. This was the only time that Washington pronounced an opinion on any of the actual issues debated during the entire convention.
In
Federalist No. 55Federalist No. 55 is an essay by James Madison, the fifty-fifth of the Federalist Papers. It was published on February 13, 1788 under the pseudonym Publius, the name under which all the Federalist Papers were published. In this paper, Madison examines the size of the United States House of...
,
James MadisonJames Madison, Jr. was an American statesman and political theorist. He was the fourth President of the United States and is hailed as the “Father of the Constitution” for being the primary author of the United States Constitution and at first an opponent of, and then a key author of the United...
addressed Anti-Federalist claims that the representation would be inadequate. Madison countered that the major inadequacies are of minimal inconvenience since these will be cured rather quickly by virtue of decennial reapportionment. He noted, however, Madison also argued against the assumption that more is better,
The
first proposed amendmentArticle the First is the first proposed amendment to the United States Constitution though it has not yet been ratified...
to the Constitution within the Bill of Rights attempted to set a pattern for growth of the House along with the population, but was never ratified.
Clemons v. Department of Commerce
A recent lawsuit,
Clemons v. Department of CommerceClemons v. Department of Commerce was a lawsuit filed in the U.S...
, sought a court order for Congress to increase the size of the House's voting membership and then reapportion the seats in accordance with the population figures of the 2010 Census. The intent of the plaintiff was to rectify the disparity of congressional district population sizes among the states that result from the present method of apportionment. Upon reaching the U.S. Supreme Court in December 2010, the holdings of the lower district and appellate courts were vacated and the case remanded to the U.S. District Court from which the case originated with instructions that the district court dismiss the case for lack of jurisdiction.
Proposed expansion
The proposed
Wyoming RuleThe Wyoming Rule is a proposal to increase the size of the United States House of Representatives so that the standard Representative-to-population ratio would be that of the smallest entitled unit, which is currently Wyoming. Under Article I of the U.S. Constitution, each U.S. state is guaranteed...
calls for expanding the House until the standard Representative-to-population ratio equals that of the smallest entitled unit (currently the state of
WyomingWyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...
). This proposal is primarily designed to address the fact that some House districts are currently nearly twice the size of others; for instance, there are about 944,000 residents in
MontanaMontana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...
's single district, compared to about 515,000 in Wyoming's.
See List of U.S. states by population.
On May 21, 2001, Rep.
Alcee HastingsAlcee Lamar Hastings is the U.S. Representative for , serving since 1993. He is a member of the Democratic Party.-Early life, education and career:...
sent a
dear colleague letterA "Dear Colleague" letter is official correspondence that is sent by a Member, committee, or officer of the United States House of Representatives or United States Senate and that is distributed in bulk to other congressional offices...
pointing out that U.S. expansion of its legislature had not kept pace with other countries.
In 2007, during the 110th Congress,
Representative Tom DavisThomas Milburn "Tom" Davis III was a Republican member of the United States House of Representatives, representing Virginia's 11th congressional district in Northern Virginia. Davis was considering a run for the U.S. Senate seat being vacated by five-term incumbent and fellow Republican John...
introduced a bill in the House of Representatives that would add two seats to the House, one for Utah and one for the District of Columbia. It was passed by the House, but was tripped up by procedural hurdles in Senate and withdrawn from consideration. An identical bill was reintroduced during the 111th Congress. In February 2009 the Senate adopted the measure 61-37. In April 2010, however, House leaders decided to shelve the proposal.
Apportionment methods
Apart from the requirement that the number of delegates for each state is at least one, a state's number of representatives is in principle proportional to population, thus assuring reasonably consistent representation to the people regardless of the state boundaries and populations. No method of calculating a fair distribution of voting power across the various states was known until recently and five distinct apportionment methods have been used since the adoption of the
ConstitutionThe Constitution of the United States is the supreme law of the United States of America. It is the framework for the organization of the United States government and for the relationship of the federal government with the states, citizens, and all people within the United States.The first three...
, none of them producing fully proportional distribution of power among the states. Some of these methods were even susceptible to the
apportionment paradoxAn apportionment paradox exists when the rules for apportionment in a political system produce results which are unexpected or seem to violate common sense.To apportion is to divide into parts according to some rule, the rule typically being one of proportion...
. In 2008, however, a so-called One-Person-One-Vote model was introduced by J. Toplak in Temple Law Review, which distributes the states' power in the House of Representatives exactly 'according to their Numbers'. Under this system, however, members of the House of Representatives do not have equal voting power. The method would be constitutional since the U.S. Constitution does not require Congressmen to have equal voting powers but does require the voters to have votes of equal weight.
The Method of Equal Proportions
The apportionment methodology currently used is the method of equal proportions, so called because it guarantees that no additional transfer of a seat (from one state to another) will reduce the ratio between the numbers of persons per representative in any two states. According to
NationalAtlas.gov, the method of equal proportions minimizes the percentage differences in the size of the congressional districts.
In this method, as a first step, each of the 50 states is given its one guaranteed seat in the House of Representatives, leaving 385 seats to assign.
The remaining seats are allocated one at a time, to the state with the highest priority number. Thus, the 51st seat would go to the most populous state (currently California). The priority number is determined by a formula that is mathematically computed to be the ratio of the state population to the
geometric meanThe geometric mean, in mathematics, is a type of mean or average, which indicates the central tendency or typical value of a set of numbers. It is similar to the arithmetic mean, except that the numbers are multiplied and then the nth root of the resulting product is taken.For instance, the...
of the number of seats it currently holds in the assignment process,
n (initially 1), and the number of seats it
would hold
if the seat were assigned to it,
n+1.
The formula for determining the priority of a state to be apportioned the next available seat defined by the method of equal proportions is
where
P is the population of the state, and
n is the number of seats it currently holds before the possible allocation of the next seat. An equivalent, recursive definition is
where
n is still the number of seats the state has before allocation of the next, and for
n = 1, the initial
A1 is explicitly defined as
Consider the reapportionment following the 2000 U.S. Census: beginning with all states initially being allocated one seat, the largest value of
A1 corresponds to the largest state, California, which is allocated seat 51. After being allocated its 2nd seat, its priority value decreases to its
A2 value, which is reordered to a position back in line. The 52nd seat goes to Texas, the 2nd largest state, because its
A1 priority value is larger than the
An of any other state. However, the 53rd seat goes back to California because its
A2 priority value is larger than the
An of any other state. The 54th seat goes to New York because its
A1 priority value is larger than the
An of any other state at this point. This process continues until all remaining seats are assigned. Each time a state is assigned a seat,
n is incremented by 1, causing its priority value to be reduced and reordered among the states, whereupon another state normally rises to the top of the list.
The Census 2010 Ranking of Priority Values shows the order in which seats 51–435 were apportioned after the 2010 Census, with additional listings for the next five priorities.
MinnesotaMinnesota is a U.S. state located in the Midwestern United States. The twelfth largest state of the U.S., it is the twenty-first most populous, with 5.3 million residents. Minnesota was carved out of the eastern half of the Minnesota Territory and admitted to the Union as the thirty-second state...
was allocated the final (435th) seat.
North CarolinaNorth Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
, which gained the 435th seat in the 2000 census, missed its 14th seat by 15,754 residents as the 436th seat to be allocated.
Past apportionments
Changes following the 2010 census
On December 21, 2010 the U.S. Census Bureau released its official apportionment results for congressional representation. The changes will be in effect for the
U.S. elections in 2012The 2012 United States elections will be held on Tuesday, November 6, 2012. The 57th quadrennial presidential election will be held on this date, coinciding with Senate elections where 33 races will occur, as well as House of Representatives elections to elect the members for the 113th Congress...
, provided no legal challenges to the results significantly change the results.
| Gain four |
Gain two |
Gain one |
Lose one |
Lose two |
TexasTexas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
|
FloridaFlorida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
|
ArizonaArizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
GeorgiaGeorgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...
NevadaNevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
South CarolinaSouth Carolina is a state in the Deep South of the United States that borders Georgia to the south, North Carolina to the north, and the Atlantic Ocean to the east. Originally part of the Province of Carolina, the Province of South Carolina was one of the 13 colonies that declared independence...
UtahUtah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
Washington |
IllinoisIllinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...
IowaIowa is a state located in the Midwestern United States, an area often referred to as the "American Heartland". It derives its name from the Ioway people, one of the many American Indian tribes that occupied the state at the time of European exploration. Iowa was a part of the French colony of New...
LouisianaLouisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...
MassachusettsThe Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...
MichiganMichigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
MissouriMissouri is a US state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2010 population of 5,988,927, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It...
New JerseyNew Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...
PennsylvaniaThe Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...
|
New YorkNew York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...
OhioOhio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...
|
Past increases
The size of the
U.S. HouseThe United States House of Representatives is one of the two Houses of the United States Congress, the bicameral legislature which also includes the Senate.The composition and powers of the House are established in Article One of the Constitution...
has increased as follows:
1789–1800
| Date | | Size | | ∆ | Citation | Comments |
| March 4, 1789 |
59 |
n/a |
Const. Art. I,
§ 2, cl. 3 |
Seats apportioned by the Constitution |
| November 21, 1789 |
64 |
+5 |
North CarolinaNorth Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
ratified the Constitution with the seats apportioned by the Constitution |
| May 29, 1790 |
65 |
+1 |
Rhode IslandThe state of Rhode Island and Providence Plantations, more commonly referred to as Rhode Island , is a state in the New England region of the United States. It is the smallest U.S. state by area...
ratified the Constitution with the seats apportioned by the Constitution |
| March 4, 1791 |
67 |
+2 |
|
VermontVermont is a state in the New England region of the northeastern United States of America. The state ranks 43rd in land area, , and 45th in total area. Its population according to the 2010 census, 630,337, is the second smallest in the country, larger only than Wyoming. It is the only New England...
admitted |
| June 1, 1792 |
69 |
+2 |
KentuckyThe Commonwealth of Kentucky is a state located in the East Central United States of America. As classified by the United States Census Bureau, Kentucky is a Southern state, more specifically in the East South Central region. Kentucky is one of four U.S. states constituted as a commonwealth...
admitted |
| March 4, 1793 |
105 |
+36 |
|
Apportionment of the First Census The United States Census of 1790 was the first census conducted in the United States. It recorded the population of the United States as of Census Day, August 2, 1790, as mandated by Article I, Section 2 of the United States Constitution and applicable laws...
|
| June 1, 1796 |
106 |
+1 |
|
TennesseeTennessee is a U.S. state located in the Southeastern United States. It has a population of 6,346,105, making it the nation's 17th-largest state by population, and covers , making it the 36th-largest by total land area...
admitted |
1801–1820
| Date | | Size | | ∆ | Citation | Comments |
| March 1, 1803 |
107 |
+1 |
|
OhioOhio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...
admitted. |
| March 4, 1803 |
142 |
+35 |
|
Apportionment of the Second Census The United States Census of 1800 was the second Census conducted in the United States. It was conducted on August 4, 1800.It showed that 5,308,483 people were living in the United States of which 893,602 were slaves. The 1800 Census included the new District of Columbia...
. |
| April 30, 1812 |
143 |
+1 |
|
LouisianaLouisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...
admitted. |
| March 4, 1813 |
182 |
+39 |
|
Apportionment of the Third Census The United States Census of 1810 was the third Census conducted in the United States. It was conducted on August 6, 1810. It showed that 7,239,881 people were living in the United States of which 1,191,362 were slaves....
. |
| December 11, 1816 |
183 |
+1 |
|
IndianaIndiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is...
admitted. |
| December 10, 1817 |
184 |
+1 |
|
MississippiMississippi is a U.S. state located in the Southern United States. Jackson is the state capital and largest city. The name of the state derives from the Mississippi River, which flows along its western boundary, whose name comes from the Ojibwe word misi-ziibi...
admitted. |
| December 3, 1818 |
185 |
+1 |
|
IllinoisIllinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...
admitted. |
| December 14, 1819 |
186 |
+1 |
|
AlabamaAlabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...
admitted. |
| March 15, 1820 |
n/c |
|
MaineMaine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south, New Hampshire to the west, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is both the northernmost and easternmost...
admitted, given seven seats. MassachusettsThe Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...
delegation reduced correspondingly |
1821–1840
| Date | | Size | | ∆ | Citation | Comments |
| August 10, 1821 |
187 |
+1 |
|
MissouriMissouri is a US state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2010 population of 5,988,927, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It...
admitted |
| March 4, 1823 |
213 |
+26 |
|
Apportionment of the Fourth Census The United States Census of 1820 was the fourth Census conducted in the United States. It was conducted on August 7, 1820 The total population was determined to be 9,638,453 of which 1,538,022 were slaves...
|
| March 4, 1833 |
240 |
+27 |
|
Apportionment of the Fifth Census The United States Census of 1830 was the fifth Census conducted in the United States. It was conducted on June 1, 1830. It determined the population of the 24 states to be 12,866,020 of which 2,009,043 were slaves. The center of population was about 170 miles west of Washington, D.C...
|
| June 15, 1836 |
241 |
+1 |
|
ArkansasArkansas is a state located in the southern region of the United States. Its name is an Algonquian name of the Quapaw Indians. Arkansas shares borders with six states , and its eastern border is largely defined by the Mississippi River...
admitted |
| January 26, 1837 |
242 |
+1 |
|
MichiganMichigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
admitted |
1841–1860
| Date | | Size | | ∆ | Citation | Comments |
| March 4, 1843 |
223 |
−19 |
|
Apportionment of the Sixth Census The United States Census of 1840 was the sixth census of the United States. Conducted by the Bureau of the Census on June 1, 1840, it determined the resident population of the United States to be 17,069,453 — an increase of 32.7 percent over the 12,866,020 persons enumerated during the 1830...
, the only time the size of the House was reduced, except for the minor readjustment in 1963. |
| March 3, 1845 |
224 |
+1 |
|
FloridaFlorida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
admitted. |
| December 29, 1845 |
226 |
+2 |
|
Texas annexed In 1845, United States of America annexed the Republic of Texas and admitted it to the Union as the 28th state. The U.S. thus inherited Texas's border dispute with Mexico; this quickly led to the Mexican-American War, during which the U.S. captured additional territory , extending the nation's...
and admitted. |
| December 28, 1846 |
228 |
+2 |
|
IowaIowa is a state located in the Midwestern United States, an area often referred to as the "American Heartland". It derives its name from the Ioway people, one of the many American Indian tribes that occupied the state at the time of European exploration. Iowa was a part of the French colony of New...
admitted. |
| May 29, 1848 |
230 |
+2 |
|
WisconsinWisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...
admitted. |
| March 4, 1849 |
231 |
+1 |
|
Wisconsin given another seat. |
| September 9, 1850 |
233 |
+2 |
|
CaliforniaCalifornia is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
admitted. |
| March 4, 1853 |
234 |
+1 |
|
Apportionment of the Seventh Census The United States Census of 1850 was the seventh census of the United States. Conducted by the Bureau of the Census on June 1, 1850, it determined the resident population of the United States to be 23,191,876 — an increase of 35.9 percent over the 17,069,453 persons enumerated during the 1840...
. |
| May 11, 1858 |
236 |
+2 |
|
MinnesotaMinnesota is a U.S. state located in the Midwestern United States. The twelfth largest state of the U.S., it is the twenty-first most populous, with 5.3 million residents. Minnesota was carved out of the eastern half of the Minnesota Territory and admitted to the Union as the thirty-second state...
admitted. |
| February 14, 1859 |
237 |
+1 |
|
OregonOregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
admitted. |
1861–1880
| Date | | Size | | ∆ | Citation | Comments |
| January 29, 1861 |
238 |
+1 |
|
KansasKansas is a US state located in the Midwestern United States. It is named after the Kansas River which flows through it, which in turn was named after the Kansa Native American tribe, which inhabited the area. The tribe's name is often said to mean "people of the wind" or "people of the south...
admitted |
| June 2, 1862 |
239 |
+1 |
|
California apportioned an extra seat |
| March 4, 1863 |
241 |
+2 |
|
Apportionment of the Eighth Census The United States Census of 1860 was the eighth Census conducted in the United States. It determined the population of the United States to be 31,443,321 — an increase of 35.4 percent over the 23,191,875 persons enumerated during the 1850 Census...
|
| June 20, 1863 |
n/c |
|
West Virginia admitted and given three seats. Virginia's delegation reduced in census reapportionment |
| October 31, 1864 |
242 |
+1 |
|
NevadaNevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
admitted |
| March 1, 1867 |
243 |
+1 |
|
NebraskaNebraska is a state on the Great Plains of the Midwestern United States. The state's capital is Lincoln and its largest city is Omaha, on the Missouri River....
admitted |
| March 4, 1873 |
283 |
+40 |
|
Apportionment of the Ninth Census The United State Census of 1870 was the ninth United States Census. Conducted by the Census Bureau in June 1870, the 1870 Census was the first census to provide detailed information on the black population, only years after the culmination of the Civil War when slaves were granted freedom. The...
|
| 292 |
+9 |
|
Supplemental apportionment added one seat each for nine states |
| August 1, 1876 |
293 |
+1 |
|
ColoradoColorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
admitted |
1881–1900
| Date | | Size | | ∆ | Citation | Comments |
| March 4, 1883 |
325 |
+32 |
|
Apportionment of the Tenth Census The United States Census of 1880 was the tenth United States Census conducted by the Census Bureau during June 1880. It was the first time that women were permitted to be enumerators...
. |
| November 2, 1889 |
328 |
+3 |
|
North DakotaNorth Dakota is a state located in the Midwestern region of the United States of America, along the Canadian border. The state is bordered by Canada to the north, Minnesota to the east, South Dakota to the south and Montana to the west. North Dakota is the 19th-largest state by area in the U.S....
and South DakotaSouth Dakota is a state located in the Midwestern region of the United States. It is named after the Lakota and Dakota Sioux American Indian tribes. Once a part of Dakota Territory, South Dakota became a state on November 2, 1889. The state has an area of and an estimated population of just over...
admitted. One seat goes to the former, two to the latter. |
| November 8, 1889 |
329 |
+1 |
|
MontanaMontana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...
admitted. |
| November 11, 1889 |
330 |
+1 |
|
Washington admitted. |
| July 3, 1890 |
331 |
+1 |
|
IdahoIdaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
admitted. |
| July 10, 1890 |
332 |
+1 |
|
WyomingWyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...
admitted. |
| March 4, 1893 |
356 |
+24 |
|
Apportionment of the Eleventh Census The Eleventh United States Census was taken June 2, 1890. The data was tabulated by machine for the first time. The data reported that the distribution of the population had resulted in the disappearance of the American frontier...
. |
| January 4, 1896 |
357 |
+1 |
|
UtahUtah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
admitted. |
1901–present
| Date | | Size | | ∆ | Citation | Comments |
| March 4, 1903 |
386 |
+29 |
|
Apportionment of the Twelfth Census The Twelfth United States Census, conducted by the Census Office on June 1, 1900, determined the resident population of the United States to be 76,212,168, an increase of 21.0 percent over the 62,979,766 persons enumerated during the 1890 Census....
|
| November 16, 1907 |
391 |
+5 |
|
OklahomaOklahoma is a state located in the South Central region of the United States of America. With an estimated 3,751,351 residents as of the 2010 census and a land area of 68,667 square miles , Oklahoma is the 28th most populous and 20th-largest state...
admitted |
| January 6, 1912 |
392 |
+1 |
|
New MexicoNew Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
admitted |
| February 14, 1912 |
393 |
+1 |
|
ArizonaArizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
admitted |
| March 4, 1913 |
435 |
+42 |
Public Law 62-5 -Subsequent apportionment:For the first and only time, Congress failed to pass an apportionment act after the 1920 census. This left the allocations of the Act of 1911 in place until the 1930 census. The Reapportionment Act of 1929 established a method for reallocating seats among the states,...
|
Apportionment of the Thirteenth Census The Thirteenth United States Census, conducted by the Census Bureau on April 15, 1910, determined the resident population of the United States to be 92,228,496, an increase of 21.0 percent over the 76,212,168 persons enumerated during the 1900 Census...
|
| January 3, 1959 |
436 |
+1 |
|
AlaskaAlaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
admitted |
| August 21, 1959 |
437 |
+1 |
|
HawaiiHawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
admitted |
| January 3, 1963 |
435 |
−2 |
Reapportionment Act of 1929 The Reapportionment Act of 1929 was a combined census and reapportionment bill passed by the United States Congress that established a permanent method for apportioning a constant 435 seats in the U.S. House of Representatives according to each census...
|
Apportionment of the Eighteenth Census The Eighteenth United States Census, conducted by the Census Bureau, determined the resident population of the United States to be 179,323,175, an increase of 18.5 percent over the 151,325,798 persons enumerated during the 1950 Census.-Census questions:...
|
See also
- Apportionment paradox
An apportionment paradox exists when the rules for apportionment in a political system produce results which are unexpected or seem to violate common sense.To apportion is to divide into parts according to some rule, the rule typically being one of proportion...
- Article the First
Article the First is the first proposed amendment to the United States Constitution though it has not yet been ratified...
- Gerrymandering
In the process of setting electoral districts, gerrymandering is a practice that attempts to establish a political advantage for a particular party or group by manipulating geographic boundaries to create partisan, incumbent-protected districts...
- List of U.S. states by population
- List of U.S. states by historical population (tables of state populations since 1790)
- Redistricting
Redistricting is the process of drawing United States electoral district boundaries, often in response to population changes determined by the results of the decennial census. In 36 states, the state legislature has primary responsibility for creating a redistricting plan, in many cases subject to...
- United States Congress
The United States Congress is the bicameral legislature of the federal government of the United States, consisting of the Senate and the House of Representatives. The Congress meets in the United States Capitol in Washington, D.C....
External links