Most collegiate teams play in athletic conferences. Among the best-known are the Ivy League, Big Ten, Atlantic Coast, Southeastern, and Pacific 10 conferences. With an atmosphere enhanced by bands and cheering sections, football is not only the most popular collegiate sport of the fall season but also a big business. Revenues from football often finance other sports at a college, and some games are played before crowds of 100,000 people in university-owned stadiums. Despite the strict amateur code of the National Collegiate Athletic Association and its member conferences, illegal subsidization of football players is a recurrent issue.
Football also is extremely popular in U.S. high schools.
Six-man football and touch football, both usually played for recreation, are other forms of the amateur game. Although professional football was played as early as 1895 in Pennsylvania, it was not until 1920 that national organization began, with the formation of the American Professional Football Association at Canton, Ohio. Other college stars soon followed, and the public began to show interest in NFL teams. In the period immediately following World War II professional football's popularity grew tremendously. B. Carroll et al., ed.