The United States Army in the Eastern Theater

< to March • April 1862 • to May >

Commanded by Major General George B. McClellan (until April 4)

After April 4, 1862 there was no commander in chief of the army. Direction came from the President and the War Department.

Army of the Potomac
Major General George B. McClellan

Department of Virginia
Major General John E. Wool

Middle Department
Major General John Dix

Military District of Washington
Brigadier General James Wadsworth
Transferred into the Department of the Rappahannock (below) April 4

Mountain Department
Major General John C. Fremont

Department of the Rappahannock (established April 4) 
Major General Irvin McDowell
Consisting of Virginia east of the Blue Ridge and west of the Potomac River, the Fredericksburg and Richmond Railroad, including the District of Columbia and the country between the Potomac and the Patuxent Rivers.

Department of the Shenandoah (re-established April 4)
Major General Nathaniel Banks
Consisting of the Valley of Virginia and Allegheny & Washington Counties in Maryland.