 Posted along Bull Run near the Bull Run battlefield, the regiment stood picket duty and guarded against the partisan guerrillas of Confederate Col. John S. Mosby.On February 10, the regiment received orders to march to the main winter quarters of the Army of the Potomac at Belle Plain, Virginia.There, the regiment was reassigned and brigaded with the 121st Pennsylvania, 142nd Pennsylvania, and 80th New York under the command of Brigadier General Thomas Rowley.