Teams meet in Canton and form what becomes the NFL. Pro football gets a schedule, a name, and a future that will outgrow the room.
September 1920, a Hupmobile showroom in Canton, Ohio. Men from Ohio, New York, and a handful of other towns agree to a league. It will be called the American Professional Football Association, then the NFL. Jim Thorpe is the first president. The money is small. The idea is a circuit instead of barnstorming.
Decades of folding teams, rule tweaks, and a merger later, the Super Bowl is the national holiday. The origin is still a room full of owners who wanted to stop poaching players and start selling tickets on a calendar.
American pro football does not begin as a spectacle. It begins as a pact. Canton keeps the Hall of Fame because this is where the pact was signed.