1861
July 23 –
October 25
Organized at Washington, D.C. under Colonel James A. Tait
October-
November
Duty in the Defenses of Washington, D.C. attached to Provisional Brigade, Casey’s Division, Army of the Potomac
November Assigned to Robinson’s Brigade, Army of the Potomac
December Railroad guard near Bladensburg, Md.
1862
May 24-30 Ordered to Harper’s Ferry and attached to Miles’ Command, Harper’s Ferry
June Operations in the Shenandoah Valley, Va. assigned to 2nd Brigade, Sigel’s Division, Dept. of the Shenandoah
July Assigned to 2nd Brigade, 2nd Division, 2nd Army Corps, Army of Virginia, which was commanded by Colonel Tait
August 9 Battle of Cedar Mountain
August 16-
September 2
Pope’s Campaign in Northern Virginia. Assigned to 3rd Brigade, 2nd Division, 2nd Army Corps, Army of Virginia, commanded by Colonel Tait
August 28-26 Fords of the Rappahannock
August 27-29 Plains of Manassas
August 29-30 Second Battle of Bull Run (Reserve)
September Moved to Washington, D.C. and duty in the defenses of that city and Alexandria, Va. attached to 3rd Brigade, 2nd Division, 12th Army Corps, Army of the Potomac
September 17
Battle of Antietam

The division commander, Brigadier General George Greene, wrote in his report that the regiment “had, with the exception of the colonel and adjutant, entirely disappeared from the command by sickness and desertion.”

October Assigned to District of Alexandria, Defenses of Washington, D. C.
November 13 Colonel Tait was appointed Provost Marshall General, Defenses South of the Potomac
1863
February Assigned to Slough’s Command, Defenses of Alexandria, 22nd Army Corps, Dept. of Washington.
21 September Colonel Tait was dismissed for allowing contraband to pass to the Confederacy during his tenure as Provost Marshall. He had been acquitted by a Court Martial but the verdict was overruled by the Department Commander, General Heintzelman, who was supported by President Lincoln.
1864
July 11-13 Repulse of Early’s attack on Washington
1865
February 28 Consolidated with 2nd Regiment District of Columbia Infantry