Potomac Aqueduct

The Potomac Aqueduct survives as a series of heavy stone piers rising out of the river like broken teeth. This structure once carried the Chesapeake and Ohio Canal across the water to Alexandria, Virginia, in a wooden trough suspended atop those granite foundations. In eighteen sixty-one, Union soldiers drained the canal and turned the trough into a fortified bridge to block Confederate forces from crossing. The aqueduct carried water for commerce for decades, then soldiers for war, before its removal in the nineteen thirties.