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Dennis Hart Mahan

 
Dennis Hart Mahan

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Dennis Hart Mahan



 
 
Dennis Hart Mahan (April 2, 1802 – September 16, 1871) was a noted American
United States

The United States of America is a Federal government constitutional republic comprising U.S. state and a federal district. The country is situated mostly in central North America, where its Contiguous United States and Washington, D.C., the Capital districts and territories, lie between the Pacific Ocean and Atlantic Oceans, Borders of the U...
 military theorist
Military theory

Military theory is the analysis of Norm behavior and trends in military affairs and military history. Beyond simply describing events in war, military theories, especially since the influence of Carl von Clausewitz in the nineteenth century, attempt to encapsulate the complex cultural, political, and economic relationships between societies...
 and professor at the United States Military Academy
United States Military Academy

The United States Military Academy at West Point is a four-year coeducational United States Service academies located at West Point, New York, New York....
 at West Point
West Point, New York

West Point is a federal military reservation located North of the Highland Falls, New York in Orange County, New York, United States. The population was 7,138 at the 2000 census....
 from 1824-1871. He was the father of American naval historian and theorist Rear Admiral Alfred Thayer Mahan
Alfred Thayer Mahan

Alfred Thayer Mahan was a United States Navy flag officer, Geostrategy, and educator. His ideas on the importance of sea power influenced navies around the world, and helped prompt naval buildups before World War I....
. Of his other four children, his son Frederick August Mahan also graduated from West Point in 1867.

is Hart Mahan was the child of Irish-Catholic immigrants.






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Dennis Hart Mahan
Dennis Hart Mahan (April 2, 1802 – September 16, 1871) was a noted American
United States

The United States of America is a Federal government constitutional republic comprising U.S. state and a federal district. The country is situated mostly in central North America, where its Contiguous United States and Washington, D.C., the Capital districts and territories, lie between the Pacific Ocean and Atlantic Oceans, Borders of the U...
 military theorist
Military theory

Military theory is the analysis of Norm behavior and trends in military affairs and military history. Beyond simply describing events in war, military theories, especially since the influence of Carl von Clausewitz in the nineteenth century, attempt to encapsulate the complex cultural, political, and economic relationships between societies...
 and professor at the United States Military Academy
United States Military Academy

The United States Military Academy at West Point is a four-year coeducational United States Service academies located at West Point, New York, New York....
 at West Point
West Point, New York

West Point is a federal military reservation located North of the Highland Falls, New York in Orange County, New York, United States. The population was 7,138 at the 2000 census....
 from 1824-1871. He was the father of American naval historian and theorist Rear Admiral Alfred Thayer Mahan
Alfred Thayer Mahan

Alfred Thayer Mahan was a United States Navy flag officer, Geostrategy, and educator. His ideas on the importance of sea power influenced navies around the world, and helped prompt naval buildups before World War I....
. Of his other four children, his son Frederick August Mahan also graduated from West Point in 1867.

Biography

Dennis Hart Mahan was the child of Irish-Catholic immigrants. He was baptized at New York City
New York City

The City of New York is the List of United States cities by population in the United States, while the New York metropolitan area ranks among the List of urban areas by population....
, though like other immigrant children of that era, e.g., General Philip Sheridan
Philip Sheridan

Philip Henry Sheridan was a career United States Army officer and a Union Army General officer in the American Civil War. His career was noted for his rapid rise to Major general and his close association with Lieutenant general Ulysses S....
, it is unclear whether Mahan was born at New York or in Ireland
Ireland

Ireland is the List of islands by area in Europe, and the twentieth-largest island in the world. It lies to the north-west of continental Europe and is surrounded by hundreds of islands and islet....
. Mahan graduated from West Point in 1824, first in his class. Such was his acumen that in his third year he was appointed acting assistant professor of mathematics. After graduation, he started teaching at the Military Academy with the very next class of cadets (1824). In 1826, he was sent to Europe
Europe

Europe is, conventionally, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally divided from Asia to its east by the water divide of the Ural Mountains, the Ural , the Caspian Sea, and by the Caucasus Mountains to the southeast....
 to study advanced engineering techniques and military institutions. Upon returning to West Point in 1830, he was promoted to Professor of Civil and Military Engineering. He resigned his commission in 1832 to accept the position of Chair of the Engineering Department.

An important influence on the military conduct of the American Civil War
American Civil War

The American Civil War , also known as the War Between the States and several Naming the American Civil War, was a civil war in the United States....
 and Civil Engineering, Mahan is best understood as an educator and technology transfer agent, not a theorist. Mahan almost singlehandedly compiled and transferred the best of European engineering to the United States and other English-speaking parts of the world. Virtually all 19th century American engineering schools were started with West Point-educated faculty or adopted its texts.

As a teacher of military science at West Point, in addition to engineering methodology, Mahan promoted the development of professionalism and wrote extensively on fixed fortifications, field fortifications, strategy and tactics. His books on military thought were widely influential. His writings became standard textbooks in the worldwide field from the time they were written until after World War I
World War I

World War I, or the First World War , was a global military conflict which involved the Great powers, organized into two opposing military alliances: the Allies of World War I and the Central Powers....
. Mahan also founded the Napoleon Seminar at West Point, where advanced under-graduates and senior officers including Lee
Robert E. Lee

Robert Edward Lee , was a career United States United States Army officer , an engineer, and among the most celebrated generals in American history....
, Reynolds
John F. Reynolds

John Fulton Reynolds was a career United States Army officer and a General officer in the American Civil War. One of the Union Army's most respected senior commanders, despite having a relatively limited amount of combat experience in the war, he played a key role in committing the Army of the Potomac to the Battle of Gettysburg and was kill...
, Thomas
Edward Lloyd Thomas

Edward Lloyd Thomas was a Confederate States Army infantry general during the American Civil War from the state of Georgia ....
 and McClellan
George B. McClellan

George Brinton McClellan was a Major general during the American Civil War. He organized the famous Army of the Potomac and served briefly as the general-in-chief of the Union Army....
, studied and discussed the great European wars, Napoleon and Frederick the Great.

Professor Mahan's lectures and writings about military fortifications and strategy were instrumental in the conduct of the Civil War by the officers on both sides. Most of the Civil War commanders, whether Union
Union Army

The Union Army was the army that fought for the Union during the American Civil War. It was also known as the Federal Army, the U.S....
 or Confederate, learned about entrenchment
Entrenchment

Entrenchment may refer to:* A method of trench digging, particularly with relation to Trench warfare.* A type of fortification created by digging ....
, fortification
Fortification

Fortifications are military constructions and buildings designed for defense in warfare and military bases. Humans have constructed defensive works for many thousands of years, in a variety of increasingly complex designs....
s, and how to conduct warfare in the classes that he taught at West Point, and from his pre-Civil War writings.

While the influence of Mahan and West Point on the Civil War remains controversial and neglected, it is not difficult to find many of the Civil War's tactics and strategies presaged in Mahan's work. Topography and the use of terrain to advantage became important thanks to Mahan, as well as the principles of concentration, "celerity" and calculated risk. Lee used the Blue Ridge Mountains
Blue Ridge Mountains

The Blue Ridge, or Blue Ridge Mountains, is a Physiographic regions of the world of the larger Appalachian Mountains division. The province consists of the Northern and Southern physiographic sections, which divide near the Roanoke River gap....
 to screen his invasions of Pennsylvania
Pennsylvania

The Commonwealth of Pennsylvania , often colloquially referred to as PA by natives and Northeasterners, is a U.S. state located in the Northeastern United States and Mid-Atlantic States regions of the United States....
 and Maryland
Maryland

Maryland is a U.S. state located in the Mid Atlantic States of the United States, bordering Virginia, West Virginia and the Washington, D.C. to the south and west, Pennsylvania to the north, and Delaware to the east....
. Grant
Ulysses S. Grant

Ulysses S. Grant, born Hiram Ulysses Grant , was an United States general and the List of Presidents of the United States President of the United States ....
 used rivers to screen his approaches to Vicksburg and Richmond
History of Richmond, Virginia

The history of Richmond, Virginia as a modern city dates to the early seventeenth century, and is crucial to the development of the colony of Virginia, the United States Revolutionary War, and the American Civil War....
. The French called this envelopment strategy "la manoeuvre sur les derrières." At Vicksburg, after the envelopment, Grant used a strategy of the central position to defeat his opponent in detail, a Napoleon tactic well-known to Mahan's admirer and Grant's lieutenant WT Sherman, if not Grant himself. At Gettysburg
Battle of Gettysburg

The Battle of Gettysburg , fought in and around the town of Gettysburg, Pennsylvania, as part of the Gettysburg Campaign, was the battle with the largest number of casualties in the American Civil War and is frequently cited as the war's Turning point of the American Civil War....
, Reynolds saw the opportunity for a Corps d'Armee engagement where his leading Corps held off Confederate attacks while the mass of the Union army concentrated. The Union's disposition on Cemetery Ridge at Gettysburg is almost perfectly sited according to Mahan's recommendations in "Field Fortifications" for disrupting an opponent's artillery fire. Meade's inability to trap Lee after Gettysburg certainly had something to do with Lee heeding Mahan's advice on planning for a protected line of retreat. Perhaps the Union and Confederate armies would have adopted flexible and resilient division and corps formations in any event, but some credit for the adoption of these extremely important military formations belongs to West Point and Mahan and their contribution to the professional development of most of the Civil War's important officers.

Books by Dennis Hart Mahan

  • Treatise on Field Fortifications (1836)
  • Elementary Course of Civil Engineering (1837; revised 1868)
  • Elementary Treatise on Advanced Guard, Outposts, and Detachment Service of Troops (1847; revised, 1862)
  • Summary on the Cause of Permanent Fortifications and of the Attack and Defense of Permanent Works (1850)
  • Elementary Treatise on Industrial Drawing (1853)
  • Editor, with additions, the American edition of Mosely's Mechanical Principles of Engineering and Architecture (1856)
  • Descriptive Geometry, as applied to the Drawing of Fortifications and Stereometry (1864)
  • An Elementary Course on Military Engineering [covering] Field Fortifications, Military Mining, and Siege Operations (1865)
  • Permanent Fortifications (1867)