The regiment left for Washington, D.C., by water for Elizabethport, New Jersey, on July 8, 1861, followed by a trip via railroad. The regiment served under von Gilsa in the campaign leading up to the First Battle of Bull Run. It was in reserve with the rest of Theodore Runyon's Fourth Division, Army of the Potomac. The regiment then participated in the campaigns of John C. Frémont in western Virginia. Von Gilsa was severely wounded leading the regiment in the Battle of Cross Keys.