The United States Army in the Eastern Theater
< to July • August 1861 • to September >
Commanded by Major General Winfield Scott
Department of Pennsylvania
Major General John A. Dix
Merged into Department of the Potomac 8/24
Department of Virginia
Major General Benjamin F. Butler (until 8/17)
Major General John E. Wool
Department of Northeastern Virginia
Brigadier General Irvin McDowell
Discontinued and merged into the Department of the Potomac 8/17
Military District of the Potomac
Redesignated Department or Army of the Potomac August 15
Major General George B. McClellan
Combined with the Department of the Shenandoah 8/17 and Pennsylvania 8/24
Department of the Shenandoah
Major General Nathaniel P. Banks
Merged into Department of the Potomac 8/17
Department of the East
Major General John E. Wool
Abolished 8/17