The C&O Canal was an important transportation line during the Civil War, and was a frequent target of attack from both sides.
Confederate General Thomas J. "Stonewall" Jackson's troops attempted to breat Dam Nos. 4 & 5 in the winter of 1861-62. During the Battle of Antietam, Union Maj. Gen. George G. McClellan sent cavalry to destroy canal property at Williamsport to prevent the Confederates from crossing the river and flanking his army.
During the 1863 Gettysburg Campaign, the Confederates cut four roads through the canal to pass the southern army, tore out the four corners of the Conococheague Aqueduct, and burned the gates and dislodged two rows of stone at Lock No. 44.
[text with upper right image] Canal boat passing by Williamsport as Union troops prepare to cross the Potomac, June 1862. Detail from engraving in Frank Leslie's Illustrated Newspaper, August 1, 1863.
[text with lower image] Conococheague Aqueduct showing damage from 1863 Confederate invasion and retreat. Frank Leslie's Illustrated Newspaper, August 1, 1863.