XXII Corps was a corps in the Union army during the American Civil War. It was created on February 2, 1863, to consist of all troops garrisoned in Washington, D.C., and included three infantry divisions and one of cavalry (under Judson Kilpatrick, which left to join the Army of the Potomac during the Gettysburg campaign). Many of its units were transferred to the Army of the Potomac during Grant's Overland Campaign.

This Corps did not include the many regiments that passed through Washington, D.C., on the way to the front or away from it. Nor does it include the many regiments from the Army of the Potomac, Army of Georgia, and Army of the Tennessee that encamped in the area to participate in the Grand Review of the Armies.

History Civil War Armies at the time took their name from the Department that it was born out of. This is the reason for the naming of the Army of the Potomac, born out of the Department of the Potomac.History — Army of the Potomac At the time of the war, the Union named most of its departments, and thus its armies, after naturally occurring landmarks, specifically water courses, i.e. The Army of the Potomac, The Army of the James, The Army of the Gulf, etc. In opposition, the Confederacy named most of their Armies for geographic areas and states.

Department of the East Comprising all of the United States east of the Mississippi River, about half of which became Confederate territory. Formed on January 1, 1861, there were many Departments formed within its borders, and finally destablished August 17, 1861. Its primary focus was to employ a chain of command to all units until the smaller departments could be formed. Headquartered in Albany, New York, it was commanded by Major General John E. Wool.Boatner, p.257

Department of Washington, D.C. Constituted April 9, 1861, to include Washington, D.C., to its original boundaries of Arlington, Virginia, and the state of Maryland as far as Bladensburg. It was formed to center on the defense of the national capital, and to differentiate it from the Department of the East. The department was commanded by Lieutenant Colonel Charles F. Smith from April 10 through April 28, 1861, and Colonel (later Brigadier General) Joseph K. Mansfield from April 28, 1861, through the Department's dissolution on July 25, 1861.Boatner, p. 893

Army of the Potomac The Army of the Potomac, formed July 25, 1861, and destablished August 16, 1861, provide for the defense of the city of Washington, D.C. This Department was entrusted with the duty of protecting the United States' capital, with the construction of fortifications. Before the dissolution of the Department of the Potomac, most of the fortifications in the Washington, D.C., area were constructed, mainly by the regiments that were garrisoned there, most of whom had gone on to form the Army of the Potomac. Commanded by Major General George B. McClellan.Boatner, p. 664

Military District of Washington A Military District during the Civil War was a formation within a Department for the purpose of reporting directly to the department commander for administrative affairs.

The Military District of Washington was organized June 26, 1862, to include Washington, D.C.; Alexandria, Virginia; and Fort Washington, Maryland.General Orders No. 12 It was a District under the Department of the Potomac. It was incorporated into the Department of the Rappahanock from April 4, 1862, through June 26, 1862, when it again became an independent command. On February 2, 1863, it merged into the Department of Washington. Commanded by Brigadier General James S. Wadsworth.

Department of the Rappahannock The Department of the Rappahannock was formed April 4, 1862, from the original I Corps of the Army of the Potomac, to control the area east of the Blue Ridge Mountains to the Potomac River, the Fredericksburg and Richmond Rail Road and the District of Columbia expanded to include the area between the Potomac and Patuxent Rivers. It was merged into the Army of Virginia as III Corps on June 26, 1862, with Major General Irwin McDowell as its commander.Boatner, p.680

Defenses of Washington, D.C. The Defenses of Washington D.C. was a short lived command, from September 2, 1862, through February 2, 1863. used for the consolidation of all the defenses of the area including and surrounding Washington, D.C. Its main focus was on the maintaining of the fortifications in extending in a ring around Washington, D.C.

Department of Washington On February 2, 1863, the Department of Washington was re-formed to encompass the area from north of the Potomac from Piscataway Creek to Annapolis Junction (near present-day Fort Meade), west to the Monocacy River, south to the Bull Run Mountains by way of Goose Creek, then east to Occoquan River. The size of it would expand throughout the war to include the entirety of the counties in the surrounding states of Maryland and Virginia.

The Quartermaster Department of the Department of Washington was the largest Quartermaster Department in the Union Army. Duties as varied as building, maintenance of fortifications, supplies, road building, transportation, and ordnance testing as well as many other duties were taken over by the quartermasters of the Washington Department. Washington, D.C., also served as a transship point for supplies and materiel destined to both the Army of the Potomac and Army of the James.

XXII Corps

A Corps is a grouping of two to six divisions, providing a level of the chain of command typically commanded by a major general. Corps were first created by an Act of Congress on July 17, 1862, but Major General George B. McClellan had instituted them in the spring of 1862. Before this time, the formations were known as either "Wings" or "Grand Divisions". Most Corps came under the operational command of an Army, but the XXII Corps did not.

XXII Corps was formed as a Corps under the Department of Washington on February 2, 1863. As was tradition, its commanders doubled as commanders of the Department of Washington. During its time, many of the regiments that were fought out arrived to reconstitute and would then be transferred back out, most of them from or to the Army of the Potomac.

Battles Mosby's Raids During the time of existence of the 43rd Battalion Virginia Cavalry, better known as Mosby's Rangers, Mosby's Command, or Mosby's Raiders, commanded by Colonel John S. Mosby, made many forays in the area known as Mosby's Confederacy which extended from Loudoun County to Fairfax County. Many of the raids it performed came into the area protected by XXII Corps, and many skirmishes with Brigadier General William Gamble's Cavalry Division,Biography — William Gamble as well as various other XXII Corps units.History — 5th Pennsylvania Heavy Artillery During its reign, Mosby's Raiders captured Brigadier General Edwin H. Stoughton (then commanding the 2nd Vermont Brigade), cut telegraph wires during Early's Valley Campaign and numerous raids against rail lines and supply stations.Boatner, p. 571

Battle of Fort Stevens

The corps took part in the defense of Washington during Jubal Early's Washington Raid of 1864, playing a major role in the defense of Fort Stevens on July 11, 1864. Hardin's Division held the skirmish lines and engaged in small engagements, suffering 73 killed and wounded. The following day, Early found the works held by veteran soldiers of Major General Horatio Wright's VI Corps and Brevet Brigadier General William Emory's XIX Corps. After making a small fight, Early would withdraw, crossing back into Virginia the next day.

Command history Major General Samuel P. Heintzelman February 2, 1863 – October 13, 1863 Eicher, p. 862Boatner, p. 392 Major General Christopher C. AugurOctober 13, 1863 – June 11, 1865 Boatner, p. 34 Major General John G. ParkeJune 7, 1865 – June 26, 1865 Boatner, p. 618-619

Notable officers NameUnitDates ServedMajor General John G. BarnardChief Engineer, Department of WashingtonJuly 1, 1862 — June 5, 1864 Boatner, p. 44-45Mapping of Washington D.C.Major General Silas CaseyCommanded Casey's Division (Provisional Brigade) and served as an administrative officerJune 1862 — May 1863 Boatner, p. 131Maj. Gen. George B. McClellanCommanded Department of the PotomacJuly 25, 1861 — August 16, 1861 Major General Montgomery C. MeigsQuartermaster General of the Union Army and commander of War Department clerks during the Battle of Fort StevensMay 15, 1861 — June 30, 1865 Boatner, p. 542Brigadier General John Joseph AbercrombieCommanded Abercrombie's DivisionOctober 1862 — June 26, 1863Boatner, p. 1Brigadier General Barton S. AlexanderChief Engineer of the Defenses of Washington, D.C.July 1, 1862 — April 7, 1863Boatner, p. 6Brigadier General Robert CowdinCommanded 1st and 2nd Brigade, Abercrombie's Division October, 1862 — March 30, 1863Boatner, p. 205 Brigadier General Gustavus Adolphus DeRussyCommander of DeRussy's Division, stationed south of Washington, D.C.May 25, 1863 — August 20, 1865 Boatner, p. 237Brigadier General Martin Davis HardinCommander of Haskin's Division, stationed north of Washington, D.C.July 8, 1864 — August 2, 1865Boatner, p. 375Brigadier General Joseph Abel HaskinCommander of Haskin's Division, stationed north of Washington, D.C., later Chief of ArtilleryFebruary 2, 1863 — April 10, 1866Boatner, p. 383Biography — Brigadier General J.A. HaskinBrigadier General William GambleCommanded Cavalry DivisionDecember 21, 1863 — July 17, 1865 Brigadier General Rufus KingCommanded King's DivisionJuly 15, 1863 — October 20, 1863Boatner, p. 463 Brigadier General Joseph K. MansfieldCommanded the original Department of WashingtonApril 28, 1861 — March 15, 1862Boatner, p. 508Biography of Brigadier General J.K.F. MansfieldBrigadier General Edwin H. StoughtonCommander, 2nd Vermont BrigadeDecember 7, 1862 — March 9, 1863Colonel John Baillie McIntoshCommander of Cavalry DivisionJanuary 2, 1864 — May 2, 1864Sheridan's Lieutenants: Phil Sheridan, His Generals, and the Final Year of the Civil WarChief Aeronaut Thaddeus S. C. LoweCommander of the Union Army Balloon CorpsOctober 1861 — August 1863Biography — T.S.C. LoweEarly Balloon Flight in the United States

Components of XXII Corps Many Regiments and Brigades serving in the XXII Corps were only temporarily assigned to it. Some mainly served during times when they were reconstituting due to battle casualties, while others were trained in the vicinity of Washington before going into the field. Yet others were heavy artillery regiments assigned to the fortifications surrounding the capital. Many units, including heavy artillery regiments, left when more soldiers were needed during Grant's Overland Campaign and continued through the Richmond-Petersburg Campaign until the end of the war. Some units began serving before the XXII Corps was formed.

Famed Brigades in XXII Corps

The California Brigade was formed by Oregon Senator and Colonel Edwin Baker to have a California presence in the Eastern Theater. After the death of Colonel Baker at the Battle of Ball's Bluff, the brigade was redesignated the Philadelphia Brigade. Made up of the 1st, 2nd, 3rd, and 5th California Infantry. After redesignation as the Philadelphia Brigade, it consisted of the 69th, 71st, 72nd, and 106th Pennsylvania Infantry.California and the Civil War - California Brigade

The First New Jersey Brigade was a Brigade formed by the state of New Jersey while defending Washington, D.C. This was the first brigade in the Civil War to be formed with the intention of encompassing regiments from one state. It consisted of the 1st, 2nd, 3rd, 4th, and 10th New Jersey Infantry. By the end of the war, at different it would have up to eight New Jersey regiments.Boatner, p. 436