Upon the secession of Virginia in 1861, Beale accepted a commission in the cavalry as a lieutenant in the 9th Virginia Cavalry. He was soon promoted to captain and then major, and placed in command of Camp Lee, near his hometown of Hague, on the lower Potomac River. Being commended for his intelligence and excellent judgment, he subsequently served under Col. W. H. F. "Rooney" Lee in the 9th Virginia Cavalry in what became the Army of Northern Virginia. When Lee was promoted to brigadier general, Beale was advanced to the rank of colonel on September 15, 1862 and given command of the regiment, which included his sons. In December 1862, he led a bold expedition throughout the countryside near the Rappahannock River, capturing the Federal garrison at Leeds without losing a man.
