The idea of the Appalachian Trail started in 1921. The trail was completed in 1937 after more than ten years of work. Changes to the trail still happen every year. Thirty-one trail clubs and many partners help keep it usable. The National Park Service, United States Forest Service, and the nonprofit Appalachian Trail Conservancy manage it. Most of the trail is in forest or wild lands. Some parts go through towns, roads and farms. It passes through 14 states: Georgia, North Carolina, Tennessee, Virginia, West Virginia, Maryland, Pennsylvania, New Jersey, New York, Connecticut, Massachusetts, Vermont, New Hampshire, and Maine.