U.S.A.

Department of Northeastern Virginia (May - July 1861)

The department was created on May 27, 1861 to consist of part of Virginia east of the Allegheny Mountains and north of the James River, except an area 60 miles around Fortress Monroe. It was asigned to Brigadier General Irvin McDowell, who assumed command on May 28. McDowell was a staff officer known and favored by several members of the government. But his appointment was opposed by army commander General Winfield Scott and resented by Colonel Joseph Mansfield, the commander of the Department of Washington on whom McDowell was dependent for supplies and transportation.

Although the troops McDowell commanded are sometimes referred to as the "Army of Northeastern Virginia" there is no evidence that the term was used at the time. After the defeat at Bull Run the Department was consolidated into what would become the Army of the Potomac.

Irvin McDowell as a
Major General in 1862

Order of Battle for the Department of Northeastern Virginia

Department of Northeastern Virginia Order of Battle, June 1861

Department of Northeastern Virginia Order of Battle, July 1861

Department of Northeastern Virginia Order of Battle, August 1861

Timeline of the Department of Northeastern Virginia
May 24, 1861	Federal troops cross the Potomac and occupy Alexandria 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. Thirty-five Confederate cavalrymen, the city's only garrison, are captured without violence, but Colonel Elmer Ellsworth of the 11th New York Infantry Regiment is killed by a citizen after lowering a Confederate flag from the Marshal House Hotel.
May 27	The Department of Northeastern Virginia is created
May 28	Brigadier General Irvin McDowell assumes command
June	McDowell builds up an army of five divisions, around 30,000 men, from volunteer regiments sent by the Northern states. Many of them were enlisted for 90 days, severly limiting McDowell's options. In spite of their lack of training and experience, the Lincoln administration pushes McDowell to launch an attack into Virginia.
July 16	McDowell's advance begins
July 18	McDowell reaches Centerviile. A reconnaissance by Tyler's Division towards Backburn's Ford results in a small engagement.
July 21	Battle of Bull Run McDowell attacks Confederate positions behind Bull Run. After a day of heavy fighting, the Union attack collapses as Confederate reinforcements arrive from the Shenandoah Valley. A withdrawal toward Centerville by the inexperienced Union troops turns into a rout back to Washington. The equally exhasuted and disorganized Confederates are unable to pursue.
July 25	Department merged into the Miltary District of the Potomac under Major General George McClellan, with McDowell staying on in a subordinate posiiton.
August, 1861	Forces integrated into the Army of the Potomac

Department of Northeastern Virginia (May - July 1861)

Order of Battle for the Department of Northeastern Virginia

Timeline of the Department of Northeastern Virginia