During the Civil War, the B&O rail line was an important means of supply and communication, and at Point of Rocks the Baltimore and Ohio Railroad reached the banks of the Potomac River from Baltimore through a narrow strip of bottomland that allowed passage beyond the Blue Ridge's Catoctin and South Mountain ranges. Decades earlier, this strip had been the subject of a court fight when the Chesapeake and Ohio Canal and the railroad both sought to use it. In May 1861, Col. Thomas J. Jackson, later Gen. "Stonewall" Jackson, convinced the railroad to consolidate its coal shipments at a specific time period, then captured 56 locomotives and more than 300 rail cars by halting all train traffic west of Point of Rocks. In mid-June 1863, shortly before the Battle of Gettysburg, Confederate troops captured and burned a train loaded with provisions for the Union garrison at Harpers Ferry. In 1864, Confederate Lt. Col. John S. Mosby attacked the Union garrison here in what became known as the "Calico Raid" or the "Crinoline Raid." Union pickets were commonly stationed along the river during the war, while Confederate soldiers were often just across the Potomac River in Virginia.