Park, eastern U.S. It consists of the former Chesapeake and Ohio Canal, a waterway running along the Potomac River between Washington, D.C. , and Cumberland, Md.
The canal, which extends 185 mi (297 km), was built beginning in the 1820s. Competition from the railroads later caused its economic decline. The canal was purchased in 1938 by the U.S. government; it was restored and established as a historical park in 1971.