On May 26, 1861, the regiment, under Col. William H. Allen, embarked for Fortress Monroe and left the state. It served there until June 10, when it received orders to move to the support of the force at
Big Bethel and was active at the battle of that name. Returning to camp until July 3, the regiment was then ordered to Newport News and remained there until June 3, 1862, receiving over 370 recruits during the winter. The most noteworthy incident of this period was the attack on the fortifications by the
CSS Virginia on March 8, 1862. In March 1862, it was assigned to the 1st Brigade, 1st Division, Department of Virginia. From March, 1862; in the 3rd Brigade, 3rd Division,
III Corps,
Army of the Potomac. On June 6, 1862, the 1st was assigned to the 3rd Brigade, 3rd Division, III Corps, Army of the Potomac. With this brigade it was in the
Peninsula Campaign. It was engaged at Peach Orchard and
Glendale during the
Seven Days battles, losing in the latter battle 230 members killed, wounded, and missing. It then fought in the
Battle of Malvern Hill, where it was transferred to the 2nd Brigade, 1st Division, III Corps. After the battle, it was sent to Yorktown until the evacuation from the Peninsula. It returned to
Alexandria and was ordered to
Manassas, where it participated in the
Second Battle of Bull Run on August 30. It fought at
Chantilly and then remained in the defenses of Washington until October 11, 1862. At that time, it was attached to the 3rd Brigade, moved to Edwards' ferry, Middleburg and finally Falmouth, where it was stationed until the
Battle of Fredericksburg, in which it took part. Winter quarters were established at Falmouth. It took part in the
Mud March in January 1863. On May 2 and 3, 1863, the 1st was engaged at
Chancellorsville. It soon left the Army of the Potomac and headed home. On May 25, 1863, commanded by Col. J. Fred. Pierson, the men of the regiment were honorably discharged and mustered out in
New York City. ==Affiliations, battle honors, detailed service, and casualties==