The Ohio canal opened in 1827. The intent was to connect with other waterways to form a passageway from the Great Lakes to the Chesapeake Bay.

One of the first to see the benefits of connecting the Potomac to the Ohio River was George Washington, who in 1785 chartered the Patowmack Company to extend the navigability of the Potomac further North. In the beginning of the 19th century, the C&O canal was created. Work began in Georgetown July 4th 1828, the same day work began on the B&O. By 1850 the canal had only reached Cumberland, when it was decided to not go farther. Its importance was heightened during the Civil War when it supplied Washington with much needed coal. In the 1880's the B&O railroad took over the canal's operations. A disastrous flood closed the canal in 1924. In 1938 the federal government purchased the land, intending to build a parkway into DC on it. Public support, led by Justice William Douglas, favored leaving the land as it was. The roadway was not built and in 1971 it was named a National Historic park. Today the C&O canal is the least altered canal left from the great western expansion age of the United States.

Length: 184.5 miles,
Rise: 600 ft.
74 liftlocks (each lifting 8 ft.),
over 165 culverts,
111 aqueducts,
plus 12 riverfeeders and guard locks,

and 1 tunnel

Cost: $11 million

Monocacy Aqueduct: length-500ft. 7 arches
Paw Paw tunnel: length-3118 ft.