William Lathrop was a U.S. Representative

United States House of Representatives

The 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...

 from Illinois

Illinois

Illinois 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,...

.

Born near Le Roy, New York

Le Roy, New York

Le Roy, New York is the name of two locations in Genesee County, New York:*Le Roy , New York*Le Roy , New York...

, Lathrop attended the public schools and an academy at Brockport, New York

Brockport, New York

Brockport is a village located in the Town of Sweden in Monroe County, New York, USA. The population was 8,103 at the 2000 census. The name is derived from Hiel Brockway, an early settler....

.
He studied law in Attica, New York

Attica, New York

Attica is the name of some places in the U.S. state of New York:*Attica , New York, in Wyoming County*Attica , New York, in Wyoming and Genesee Counties...

.
He moved to Knoxville, Illinois

Knoxville, Illinois

Knoxville is a city in Knox County, Illinois, United States. The population was 3,183 at the 2000 census. It is part of the Galesburg Micropolitan Statistical Area.-Description:Knoxville is located just southeast of the City of Galesburg...

, and was admitted to the bar

Admission to the bar in the United States

In the United States, admission to the bar is the granting of permission by a particular court system to a lawyer to practice law in that system. Each U.S. state and similar jurisdiction has its own court system and sets its own rules for bar admission , which can lead to different admission...

 in 1850.
He settled in Rockford, Illinois

Rockford, Illinois

Rockford is a mid-sized city located on both banks of the Rock River in far northern Illinois. Often referred to as "The Forest City", Rockford is the county seat of Winnebago County, Illinois, USA. As reported in the 2010 U.S. census, the city was home to 152,871 people, the third most populated...

, in 1851 and practiced his profession.
City clerk and city attorney

City attorney

A city attorney can be an elected or appointed position in city and municipal government in the United States. The city attorney is the attorney representing the city or municipality....

 of Rockford in 1852.
He served as member of the State house of representatives in 1856 and 1857.

Lathrop was elected as a Republican

Republican Party (United States)

The Republican Party is one of the two major contemporary political parties in the United States, along with the Democratic Party. Founded by anti-slavery expansion activists in 1854, it is often called the GOP . The party's platform generally reflects American conservatism in the U.S...

 to the Forty-fifth Congress

45th United States Congress

-House of Representatives:-Leadership:-Senate:*President: William A. Wheeler *President pro tempore: Thomas W. Ferry -House of Representatives:*Speaker: Samuel J. Randall -Members:This list is arranged by chamber, then by state...

 (March 4, 1877-March 3, 1879).
He resumed the practice of law in Rockford, Illinois

Rockford, Illinois

Rockford is a mid-sized city located on both banks of the Rock River in far northern Illinois. Often referred to as "The Forest City", Rockford is the county seat of Winnebago County, Illinois, USA. As reported in the 2010 U.S. census, the city was home to 152,871 people, the third most populated...

, where he died November 19, 1907.
He was interred in Greenwood Cemetery.