United States Armies in the East


April – July 1861

The Department of Annapolis was created on April 27, 1861 to control the vital corridor from the northern states into Washington. General Orders #12 removed from the Department of Pennsylvania part of Maryland “to include the counties for twenty miles on each side of the railroad from Annapolis to Washington, as far as Bladensburg,” to become the Department of Annapolis. Brigadier General Benjamin Butler would become its first commander, but would be quickly replaced when he angered Winfield Scott.

The department was briefly renamed “Department of Maryland” before being merged into the Military District of the Potomac at the end of July.

Brigadier General (later Major General) Benjamin Butler

Brigadier General (later Major General) Benjamin Butler

Organization of the Department of Annapolis & Department of Maryland

April 1861 • May  June  July

Timeline of the Department of Annapolis & Department of Maryland, 1861
April 19
Federal troops were fired upon in the streets of Baltimore

The Sixth Massachusetts Infantry lost 3 dead and 40 wounded when attacked by a mob while transferring between train stations in Baltmore. Additional troops were turned back as they arrived, the railroad bridges into town from the north are burnt, and the only railroad into Washington D.C. from the north was cut.

April 21 Massachusetts Militia Brigadier General Benjamin F. Butler siezed the ferry Maryland at Havre de Grace and sailed the Eighth Massachusetts Infantry to Annapolis, which was connected to Washington by a branch railway line.
April 22 Butler secured Annapolis, opening up an alternative route to Washington that bypassed Baltimore.
April 27 The Department of Annapolis was created under Brigadier General Butler.
May 13 Butler secured Baltimore with a quick and bloodless occupation. General Scott was outraged that his slower and more elaborate plans were upstaged by a militia general, and ordered Butler to be relieved and transferred to command of Fort Monroe.
May 15 Major General George Cadwalader took command of the department
June 11 Major General Nathaniel P. Banks took command of the department
July 19 The department’s name was changed to the “Department of Maryland.” Major General John A. Dix took command.
July 25 The Department of Maryland was merged into the Military District of the Potomac. Departmental troops were organized as Dix’s Division.