The history of American football can be traced to early versions of rugby football and association football. Both games have their origin in varieties of football played in Britain in the mid-19th century, in which a football is kicked at a goal or kicked over a line, which in turn were based on the varieties of English public school football games.
American football resulted from several major divergences from association football and rugby football, most notably the rule changes instituted by Walter Camp, a Yale University and Hopkins School graduate, is considered to be the "Father of American Football". Among these important changes were the introduction of the line of scrimmage, of down-and-distance rules and of the legalization of interference.[1][2][3] In the late 19th and early 20th centuries, gameplay developments by college coaches such as Eddie Cochems, Amos Alonzo Stagg, Parke H. Davis, Knute Rockne, and Glenn "Pop" Warner helped take advantage of the newly introduced forward pass. The popularity of college football grew as it became the dominant version of the sport in the United States for the first half of the 20th century. Bowl games, a college football tradition, attracted a national audience for college teams. Boosted by fierce rivalries and colorful traditions, college football still holds widespread appeal in the United States.
The origin of professional football can be traced back to 1892, with William "Pudge" Heffelfinger's $500 contract to play in a game for the Allegheny Athletic Association against the Pittsburgh Athletic Club. In 1920 the American Professional Football Association was formed. This league changed its name to the National Football League (NFL) two years later, and eventually became the major league of American football. Primarily a sport of Midwestern industrial towns in the United States, professional football eventually became a national phenomenon.
The modern era of American football can be considered to have begun after the 1932 NFL Playoff game, which was the first American football game to feature hash marks, the legalization of the forward pass anywhere behind the line of scrimmage, the first indoor game since 1902, and the movement of the goal posts back to goal line. Other innovations to occur immediately after 1932, were the introduction of the AP Poll in 1934, the tapering of the ends of the football in 1934, the awarding of the first Heisman Trophy in 1935, the first NFL draft in 1936 and the first televised game in 1939. Another important event was the American football game at the 1932 Summer Olympics, which combined with a similar demonstration game at 1933 World's Fair, led to the first College All-Star Game in 1934, which in turn was an important factor in the growth of professional football in the United States.[4] American football's explosion in popularity during the second half of the 20th century can be traced to the 1958 NFL Championship Game, a contest that has been dubbed the "Greatest Game Ever Played". A rival league to the NFL, the American Football League (AFL), began play in 1960; the pressure it put on the senior league led to a merger between the two leagues and the creation of the Super Bowl, which has become the most watched television event in the United States on an annual basis