XXII Corps (ACW)

XXII Corps
Badge of the 3rd Division of the XXII Corps
Active	February 2, 1863 – June 26, 1865
Country	United States
Allegiance	Union Army
Type	Infantry and Cavalry
Colors	White background, red badge (1st Division) Blue background, white badge (2nd Division) White background, blue badge (3rd Division)
Engagements	Eastern Theater: • Valley Campaigns of 1864 • Battle of Fort Stevens • Skirmishes with Mosby's Rangers
Commanders
First Commander	Major General Samuel P. Heintzelman
Second Commander	Major General Christopher C. Augur
Third Commander	Major General John G. Parke

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.

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. 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.