The Chesapeake and Ohio Canal, also known as the C&O Canal. When it was an active canal, it paralleled the Potomac River in Maryland from Cumberland, Maryland to Washington, DC. The total length of the canal is about 182 miles. The canal way is now maintained as a park, with a linear trail following the old towpath, the C&O Canal Trail.

George Washington had a large part in its creation. George Washington founded the Potomac Company in 1785 to make improvements to the Potomac River in order to improve it's navigability. The Potomac Company built a number of skirting canals around the major falls. When completed it allowed boats and rafts to float downstream towards Georgetown. Going upstream was a bit harder. Slim boats called ?? could be slowly poled up-river.