James I. Robertson, "Ashby, Turner," American National Biography Online, February 2000, http://www.anb.org/articles/04/04-00037.html.
He and his company became part of Colonel Angus McDonald's Seventh Virginia Cavalry Regiment. Late in the spring of 1861, with Federal forces poised on the north bank of the Potomac River, Ashby demonstrated the daring for which he became famous. The Confederate officer disguised himself as an itinerant horse-doctor and traveled as far as Chambersburg, Pennsylvania, to get information on Union troops, positions, and planned movements. On 25 June Colonel McDonald urged his promotion and called Captain Ashby "one of the best partisan leaders in the service." The next day, Ashby's younger brother Richard was on a patrol when he was ambushed by a hostile force. When Turner Ashby found the body, all indications were that Richard had been stabbed several times after he fell to the ground. Thenceforth, Turner Ashby became a grim avenger against all Yankees. In November, Ashby became colonel of the Seventh Virginia Cavalry.