The United States Army in the Eastern Theater
< to June • July 1861 • to August >
Commanded by Major General Winfield Scott
Department of Pennsylvania
Major General Robert Patterson (to 7/27)
Major General John A. Dix
Department of Annapolis
Major Gen. Nathaniel Banks (to 7/19)
Renamed Department of Maryland 7/19
Major General John A. Dix (7/19 -7/25)
Merged into Deptartment of Pennsylvania 7/25
Department of Virginia
Major General Benjamin F. Butler
Department of Northeastern Virginia
Brigadier General Irvin McDowell
Department of Washington
Colonel Joseph K. F. Mansfield
Merged into the Military District of the Potomac 7/25
Military District of the Potomac (created 7/25)
Major General George B. McClellan
Combined the Departments of Maryland, Washington and Northeastern Virginia
Department of the Shenandoah (created 7/19)
Major General Nathaniel P. Banks
To consist of the Valley of Virginia, and Washington & Allegheny Counties in Maryland
Department of the East (Pre-war)
Major General John E. Wool