This song, sung to the tune of the old Scottish air Bonnie Dundee, was a tribute to Southern cavalry commander JEB Stuart.On September 5, 1862, Stuart's horsemen crossed the Potomac into Maryland at White's Ferry and set up a 20-mile-long string of outposts east of the Army of Northern Virginia. Their assignment was to warn General Robert E. Lee of the approach of the Army of the Potomac and to offer enough resistance to allow the Confederate commander time to dispose his forces for battle. The Battle of Sharpsburg (Antietam) -- the single bloodiest day in American combat history -- was fought on September 17, 1862.