The Appalachian National Scenic Trail is a public footpath across 2,144 miles of Appalachian Mountain ridgelines from Maine to Georgia and was designed, constructed, and marked in the 1920s and 1930s by volunteer hiking clubs joined together by the Appalachian Trail Conference (ATC).

Formed in 1925 and now a nonprofit organization based in Harpers Ferry, West Virginia, the ATC had the National Park Service, Forest Service, states, and local communities as active partners in the trail project from the beginning.

A "super trail" was much talked about in turn-of-the-century hiking circles of New England. "The AT" evolved from the 1921 proposals of Massachusettes regional planner Benton MacKaye to preserve the Appalachian crests as an accessible, multipurpose wilderness belt—a retreat from Eastern urban life. The old clubs that united behind MacKaye, plus the new clubs formed specifically to advance the AT idea, concentrated on the hiking aspects of his vision, under the leadership of Myron H. Avery, ATC chairman from 1931 to 1952.

The hiking clubs, the two federal agencies, states, and the Depression-era Civilian Conservation Corps combined forces to open a continuous trail by August 1937. Hurricanes, highway construction, and demands of World War II undid those efforts until 1951 saw all sections finally relocated, opened, and marked for hikers and nature lovers.

The 1968 National Trails System Act made the AT a linear national park and authorized funds to surround the entire route with public lands, either federal or state, protected from incompatible uses.