The regiment was accepted for state and federal service as the "108th Volunteers" and its designation changed to the 11th Pennsylvania Cavalry on November 13, 1861.
They remained at Camp Palmer, near Ball's Cross Roads in Washington, D.C., and practiced foot and mounted drills until an outbreak of the measles limited activities.
They remained at Camp Hamilton for six months where they built more permanent housing, ran drills, and learned how to scout.
At the start of June, the other five companies joined the Army of the Potomac at the White House, participating in operations against J.E.B.
Stuart June 13–15, and picket duty at White House and in rear of army until July 2 when they evacuated, retreating to Williamsburg.