American football is called “Football” because of its origins in two popular British sports, Rugby Football (“rugby,” for short) and Association Football (better known as “soccer”).

Both soccer-style football and rugby-style football eventually found their way to America. What resulted was an American combination of the two games. It was until much later (1906) that forward passing was allowed. So because the American game was really just another form of the European football games, it too became known as football.