Department of Washington (April - July 1861)

Lieutenant Colonel
Charles F. Smith
(pictured as a general)

Colonel Joseph
K. F. Mansfield
(pictured as a general)

The Department of Washington was established on April 9, 1861. It consisted of the District of Columba including its original territory of Alexandria County, Virginia, and the State of Maryland as far as Bladensburg.The Department was charged with the defence of the national capitol and served as the assembly point for the thousands of volunteers pouring in from all over the North to build an army to end the rebellion.

While the creation of the Department of Northeastern Virginia temporarily made the Department of Washington arear area sending supplies and reinforcements to McDowell, his defeat at Bull Run returned Washington to the front lines. But within days the Department was consolidated into what was to become the Army of the Potomac.

Order of Battle for the Department of Washington

1861: April, May, June, July

Timeline of the Department of Washington
April 9, 1861	Department established under Lieutenant Colonel Charles F. Smith
April 27-28	Colonel Joseph K. F. Mansfield takes over the department from Smith
May 24	Union troops under New York Militia General Charles W. Sandford cross the Potomac from Washington and occupy Alexandria, Virginia, to reduce the threat to Washington D.C.
May 27-28	The Department of Northeastern Virginia is created and assigned to Brigadier General Irvin McDowell.
July 21	The Federal defeat at the Battle of Bull Run returns Washington to the front line of the war.
July 25, 1861	Department consolidated with the Department of Northeastern Virginia and the Department of Maryland to form the Military District of the Potomac.

Department of Washington (April - July 1861)

Order of Battle for the Department of Washington

Timeline of the Department of Washington