Chesapeake and Ohio Canal, former waterway, c.185 mi (300 km) long, from Washington, D.C., to Cumberland, Md., running along the north bank of the Potomac River. A successor to the Potomac Company's (1784–1828) navigation improvement project, the Chesapeake and Ohio Canal was planned to extend W to Pittsburgh. Work was begun in 1828, but financial and labor problems (leading in 1834 to the first use of federal troops to settle a labor dispute), as well as opposition from the rival Baltimore and Ohio RR, delayed completion to Cumberland until 1850. Although extension to Pittsburgh proved impractical, the canal experienced a busy period in the 1870s carrying coal from the Cumberland mines. The canal was used until it was damaged by floods in 1924; in 1938 it was sold to the U.S. government. Partially restored, the canal and its towpath were proclaimed a national monument in 1961 and in 1971 became a national historical park (see National Parks and Monuments, table).
See study by G. W. Ward (1899, repr. 1973).