Other parts of the world have long had their pilgrimages, but in the United States, when it comes to doing that on foot rather than by car, I’d say the Appalachian Trail tops the list.

The public pathway was conceived in 1921, built by private citizens, and competed in 1937. It officially became the Appalachian National Scenic Trail in 1968.

Here are some other perspectives.

1. Length: Almost 2,200 miles involving 14 states from Georgia to Maine. Parts of the path get rerouted over time, a consequence of urban development pressures, loss of access across private lands, or other factors. It’s touted as the longest hiker-only trail in the world. Pack animals and wheeled things are shunted to other options.
2. Heavenly heights: The trail ascends many of the tallest peaks in the Appalachian Mountain system, including the Great Smokeys of North Carolina and Tennessee, the Green Mountains of Vermont, the Presidentials of New Hampshire, and Maine’s Longfellows, many of them rising above the tree line. Most of the trail is forests or other wildlands, although some sections, especially in the valleys, pass farmlands, follow roadways, cross bridges, or run into small towns.
3. Backpackers: Sections traversing roadways often have trailheads that give day hikers or overnighters access for short treks, the AT is celebrated for its backpackers, carrying all of their food, clothing, and gear and camping each night somewhere in the wilds. Some, like my Boy Scout troop when I was 12, venture out for a week or two, but the truly serious folks are the ones who trek from one end to the other in a single season. They’re known as thru-hikers, and those who return to hike the AT from the other direction the next year are considered a “yo-yo.” An estimated 3,000 people set out each year to hike the entire length, with a fourth of them actually succeeding. In 2017, 715 northbound and 133 southbound thru-hikers were recorded.
4. Weather factors: Winter weather in effect shuts down many sections of the AT, at least for thru-hikers. Since the weather warms earlier in Georgia than in Maine is the reason most of the thru-hikers start at the south end and head north, hoping the snow and ice have melted from northern New England sections by the time they arrive that far. Some veterans argue that the trail is easier in that direction, too.
5. Self-discovery: As one gets a distance away from a road or peopled location, the terrain becomes more pristine. There’s less litter and debris and less noise, too. The hiker encounters not only nature, on gorgeous days and raw ones, but also personal challenges and inner resources.
6. Dedicated organization: The AT is maintained by 31 trail clubs of volunteers and other partnerships and managed jointly by the National Park Service, U.S. Forest Service, and nonprofit Appalachian Trail Conservancy.
7. Angels along the way: Thru-hikers tell of remarkable locals who routinely come to the aid of the travelers. Need a bath or shower? A lift into town for groceries? A phone call, back in the day before cell phones? (Maybe today that’s a recharge?) They’re there.
8. Memories: Many of the experiences are unforgettable. The scenery, especially. But there can also be downsides: Rattlesnakes, copperheads, bears, as well as ticks, mosquitoes, and black flies. Or some brutal weather, even in the height of summer.
9. Mostly protected now: Passage of the National Trails System Act of 1968 allowed the Park System to purchase most of the lands still in private hands, assuring the AT of a permanent route.
10. It’s not necessarily free: Portions of the trail require payment for backcountry permits or park entry as well as for shelters and campsites. Otherwise, access it free. Your gear, foodstuffs, and getting there are, of course, expenses to consider.  

 The AT is no longer the only long trail system in America, but it’s still the oldest. To achieve its length combined with Continental Divide Trail (2,700 to 3,150 miles, depending) and Pacific Crest Trail (2,653 miles) is considered the Triple Crown of Hiking in the United States.