There were two

corps Corps (; plural ''corps'' ; from French , from the Latin "body") is a term used for several different kinds of organization. A military innovation by Napoleon I, the formation was first named as such in 1805. The size of a corps varies great ...

of the

Union Army During the American Civil War, the Union Army, also known as the Federal Army and the Northern Army, referring to the United States Army, was the land force that fought to preserve the Union of the collective states. It proved essential to th ...

called IV Corps during the

American Civil War The American Civil War (April 12, 1861 – May 26, 1865; also known by other names) was a civil war in the United States. It was fought between the Union ("the North") and the Confederacy ("the South"), the latter formed by state ...

. They were separate units, one serving with the

Army of the Potomac The Army of the Potomac was the principal Union Army in the Eastern Theater of the American Civil War. It was created in July 1861 shortly after the First Battle of Bull Run and was disbanded in June 1865 following the surrender of the Confede ...

and the Department of Virginia in the Eastern Theater, 1862–1863, the other with the

Army of the Cumberland The Army of the Cumberland was one of the principal Union armies in the Western Theater during the American Civil War. It was originally known as the Army of the Ohio. History The origin of the Army of the Cumberland dates back to the creatio ...

in the Western Theater, 1863–1865.

IV Corps (Eastern Theater)

The IV Corps, Army of the Potomac, was created on March 13, 1862, and placed under the command of

Erasmus D. Keyes Erasmus Darwin Keyes (May 29, 1810 – October 14, 1895) was a businessman, banker, and military general, noted for leading the IV Corps of the Union Army of the Potomac during the first half of the American Civil War. Early life and career Keyes ...

, who had commanded a brigade at

First Bull Run The First Battle of Bull Run (the name used by Union forces), also known as the Battle of First Manassas

. It consisted initially of three divisions, under Darius N. Couch, Silas Casey, and William F. "Baldy" Smith. Couch's division was transferred to join VI Corps during the Antietam Campaign and remained with them for the duration of the war. The corps' peak strength (in early 1862) was 37,000 men. The corps took part in George B. McClellan's Peninsula Campaign of 1862, playing a major role in repulsing Confederate attacks at

Seven Pines Seven Pines may refer to the following places in the United States: * Seven Pines, Virginia, in Henrico County, location of a Civil War battle and cemetery ** Battle of Seven Pines ** Seven Pines National Cemetery * Seven Pines, Mississippi, in ...

and

Malvern Hill Malvern Hill stands on the north bank of the James River in Henrico County, Virginia, USA, about eighteen miles southeast of Richmond. On 1 July 1862, it was the scene of the Battle of Malvern Hill, one of the Seven Days Battles of the Americ ...

. After the campaign, IV Corps remained on the

Peninsula A peninsula (; ) is a landform that extends from a mainland and is surrounded by water on most, but not all of its borders. A peninsula is also sometimes defined as a piece of land bordered by water on three of its sides. Peninsulas exist on al ...

, with Couch's division later detached. The corps was attached to the

Department of Virginia The Department of Virginia and North Carolina was a United States Military department encompassing Union-occupied territory in the Confederate States during the Civil War. In 1863 it was formed by the merging of two previously existing departme ...

under John A. Dix, and took part (along with VII Corps) in minor diversionary actions against Richmond during the Gettysburg Campaign. The corps was officially discontinued on August 1, 1863.Official Records, Series 1, Volume 27, Part 3, p. 827
/ref> Elements of IV Corps were later absorbed into XVIII Corps.

Command History

IV Corps (Western Theater)

This corps was created on October 10, 1863, from the remnants of XX and XXI Corps, both of which had suffered heavy casualties at

Chickamauga Chickamauga may refer to: Entertainment * "Chickamauga", an 1889 short story by American author Ambrose Bierce * "Chickamauga", a 1937 short story by Thomas Wolfe * "Chickamauga", a song by Uncle Tupelo from their 1993 album ''Anodyne'' * ''Chick ...

. It was initially commanded by

Gordon Granger Gordon Granger (November 6, 1821 – January 10, 1876) was a career U.S. Army officer and a Union general during the American Civil War, where he distinguished himself at the Battle of Chickamauga. Granger is best remembered for his part in the ...

and its division commanders were

Philip Sheridan General of the Army Philip Henry Sheridan (March 6, 1831 – August 5, 1888) was a career United States Army officer and a Union general in the American Civil War. His career was noted for his rapid rise to major general and his close as ...

, Charles Cruft, and Thomas J. Wood. It served with distinction in the famous unordered attack on

Missionary Ridge Missionary Ridge is a geographic feature in Chattanooga, Tennessee, site of the Battle of Missionary Ridge, a battle in the American Civil War, fought on November 25, 1863. Union forces under Maj. Gens. Ulysses S. Grant, William T. Sherman, ...

Chattanooga Chattanooga ( ) is a city in and the county seat of Hamilton County, Tennessee, United States. Located along the Tennessee River bordering Georgia, it also extends into Marion County on its western end. With a population of 181,099 in 2020, ...

, and served in the

Knoxville Knoxville is a city in and the county seat of Knox County in the U.S. state of Tennessee. As of the 2020 United States census, Knoxville's population was 190,740, making it the largest city in the East Tennessee Grand Division and the state ...

and

Atlanta Atlanta ( ) is the capital and most populous city of the U.S. state of Georgia. It is the seat of Fulton County, the most populous county in Georgia, but its territory falls in both Fulton and DeKalb counties. With a population of 498,71 ...

Campaigns. During John B. Hood's Franklin-Nashville Campaign, General William T. Sherman left the IV (and XXIII Corps), under the overall command of General George H. Thomas, to defend Tennessee, and the corps was heavily engaged in the battles at Spring Hill, Franklin, and

Nashville Nashville is the capital city of the U.S. state of Tennessee and the seat of Davidson County. With a population of 689,447 at the 2020 U.S. census, Nashville is the most populous city in the state, 21st most-populous city in the U.S., and t ...

. When the force Thomas commanded at Nashville was divided, he was left in command only of the IV Corps and cavalry under James H. Wilson and

George Stoneman George Stoneman Jr. (August 8, 1822 – September 5, 1894) was a United States Army cavalry officer and politician who served as the fifteenth Governor of California from 1883 to 1887. He was trained at West Point, where his roommate was Stonewal ...

. The IV Corps was ordered to block the mountain passes and prevent a potential retreat by Lee's army into the mountains. Records differ regarding the further history of the corps. Two sources report that it was deactivated on August 1, 1865. A third reports that after the war it was sent to Texas as part of the U.S. Army detachment dispatched to persuade French Emperor

Napoleon III Napoleon III (Charles Louis Napoléon Bonaparte; 20 April 18089 January 1873) was the first President of France (as Louis-Napoléon Bonaparte) from 1848 to 1852 and the last monarch of France as Emperor of the French from 1852 to 1870. A neph ...

to withdraw his troops from Mexico, and was not disbanded until December 1865.

Command History

Notes

# Eicher and Phisterer. # Fox. Stanley's personnel records indicate he commanded the Central District of Texas in June and July 1865, so a corps commander for the entire disputed period cannot be identified.

References

* Eicher, John H., & Eicher, David J., ''Civil War High Commands'', Stanford University Press, 2001, . * Fox, William F.
''Regimental Losses in the American Civil War''
reprinted by Morningside Bookshop, Dayton, Ohio, 1993, . * Phisterer, Frederick, ''Statistical Record of the Armies of the United States'', Castle Books, 1883, .

Citations

{{DEFAULTSORT:Iv Corps (Union Army) 04 Military units and formations established in 1862 1862 establishments in the United States Military units and formations disestablished in 1865