The Appalachian trail is about 2200 miles and there are competitions to run/walk it as fast as possible. The old record was about 45 days, until someone recently did it in 41 days.
But I don’t know what the record has been historically, how long it lasted, who beat the last record, etc.
Is there a list of the record breakers and their times that goes into the history of the attempts to run the AT?
https://fastestknowntime.com/route/appalachian-trail
But Peter Bakwin’s old site has more of the history,
BTW, there aren’t really any competitions to speed hike or run the AT, it’s just that people do it. The ATC doesn’t recognize any speed records but doesn’t really take any other efforts to discourage them. The only place where folks have run into problems is in Baxter State Park in Maine, the northern terminus of the trail. They have restrictions in place that can interfere with numbers of hikers allowed in each day so any support crews (or in some recent cases, camera crews) are usually excluded.
Scott Jurek was fined $500 for opening a celebratory bottle of champagne at the end of his journey, among other violations. Maine park rangers are very anti-commercialization of the wilderness.
https://www.outsideonline.com/2001076/scott-jureks-champagne-problems