 On November 26, the regiment was issued its equipment and smoothbore muskets, and sent by train to Washington, D.C.

After a halt of a few days in Washington, the 151st Pennsylvania received orders to fall in under the New York brigade of Col. Frederick George D'Utassy.D'Utassy's brigade was composed of the 39th, 111th, 125th, and 126th New York.On December 3, the 151st Pennsylvania and the four New York regiments marched away from Washington toward Union Mills, Virginia on the outer perimeter of Washington's defenses.