The Army of West Virginia was only active from August to December 1864 as a USA field army during the American Civil War.
The Army of West Virginia served in the Union Army during the American Civil War and was the primary field army of the Department of West Virginia. When Crook assumed command on August 9, 1864, the army in the field was given the title "Army of West Virginia". On December 19, 1864, with the fighting in the Valley over, the official designation as "Army of West Virginia" was discontinued but Crook retained command of the Department of West Virginia. 
