The park was established in 1961 as a National Monument by President Dwight D. Eisenhower to preserve the neglected remains of the Chesapeake and Ohio Canal and many of its original structures.

The canal and towpath trail extends along the Potomac River from the Georgetown section of Washington, D.C., to Cumberland, Maryland, a distance of 184.5 miles (296.9 km).

Only in the mid-1870s did larger locomotives and the adoption of air brakes allow the railroad to set rates lower than the canal, sealing its fate.

[10] In 1938, the abandoned canal was obtained from the B&O Railroad by the United States in exchange for a loan from the federal Reconstruction Finance Corporation.

In 1941, Harry Athey suggested to President Franklin Roosevelt that the canal could be converted into an underground highway or a bomb shelter with its roof for landing airplanes.

Because of the flooding from the 1920s to the 1940s, the Army Corps of Engineers proposed building 14 dams, that would have permanently inundated 74 miles of towpath, as well as the Monocacy and Antietam aqueducts.

[18] The idea of turning the canal over to automobiles was opposed by some, including United States Supreme Court Associate Justice William O. Douglas.

In 1958, the entire path was cleared for hiking and a 12-mile bicycle trail was built on the towpath, from Georgetown's Mule Bridge at 34th Street in Washington, DC to Widewater, a meander cutoff of the Potomac in Maryland.

[20] The bicycle trail was built by laying crushed blue stone over the muddy towpath and opened on November 22, 1958.

[24] Within ten years, the political climate had changed, and realizing that the national river plan was unsupportable, the idea of turning the canal into a historic park had little opposition.

A small portion of the towpath near Harpers Ferry National Historical Park doubles as a section of the Appalachian Trail.

The canal begins at its zero mile marker (accessible only via Thompson's Boat House), directly on the Potomac, opposite the Watergate complex.

Varied in its geography, the canal and its towpath along with the adjacent Potomac offers activities including running, hiking, biking, fishing, boating and kayaking, as well as rock climbing in certain locations.

Chesapeake and Ohio Canal National Historical Park receives around five million recreation visits annually.

Each site has a water pump (mid-April to mid-November), picnic area, firepit, and latrine;[39] nearest vehicular access points vary from 0.2 miles (0.3 km) to "remote".