Transported with his regiment to Camp Jones near Washington, D.C. in August 1861, Young and his fellow 1st Pennsylvania Cavalrymen were assigned to defensive duties there. Attached with his regiment to the Union's Army of the Potomac through April 1862 (McCall's Division through March and McDowell's I Corps through April), he and his regiment's first major engagement came in the Expedition to Dranesville beginning in late November 1861. He was then stationed with the 1st Pennsylvania Cavalry at Camp Pierpont through March 1862. Participating with his regiment in the Advance on Manassas from March 10 to 15, he then engaged in McDowell's operations in and around Falmouth from April 9 to 19 of that year. Reassigned with his regiment to Bayard's Cavalry Brigade, which was attached to the Department of the Rappahannock (until June 1862), the Army of Virginia's III Corps (to September 1862) and the Army of the Potomac to June 1863, he fought with his regiment in the battles of Cross Keys, Virginia (June 8, 1862) and Cedar Mountain (August 9); Second Battle of Bull Run (August 28–30); battles of Antietam (September 17) and Fredericksburg (August 12–15); Stoneman's 1863 Raid (April 13 to May 10, 1863); and the Battle of Brandy Station (June 9). According to historian Samuel P. Bates: