History of American football

The development of American football from nineteenth-century rugby-influenced games into a standardized, professional, and widely followed sport.

McGill–Harvard football game: A series of 1874 games between McGill and Harvard that introduced Harvard players to a rugby-style game. The 1874 contests helped establish rugby-style play at American colleges.
Intercollegiate Football Association: A college football organization founded in 1876 to establish common playing rules. Its rules helped standardize the emerging American game.
Theodore Roosevelt: The 26th president of the United States, who pressed college leaders to reform football after deadly injuries in 1905. Roosevelt convened leaders and demanded changes to reduce football deaths.
National Football League: A professional American football league founded in 1920 as the American Professional Football Association. The NFL became the dominant professional league in the sport's history.
American football in the United States: The sport's place in American institutions, regional identities, and popular culture. Football's history helps explain its unusual prominence in U.S. public life.
Walter Camp: An American football coach and rules committee member who helped shape the sport in the late nineteenth century. Camp promoted rules that distinguished American football from rugby.
Forward pass: A legal throw of the ball toward the opponent's goal line during a play. Legalizing the forward pass transformed offensive strategy in the early twentieth century.
John Heisman: An American football coach known for innovative offenses and for the trophy named in his honor. Heisman helped popularize strategic and organizational changes in college football.
American Football League: A professional league that competed with the NFL from 1960 until their 1970 merger. Its rivalry forced changes in salaries, expansion, and the professional game's structure.
Concussion in American football: A traumatic brain injury caused by a blow or jolt to the head during football. The sport's physical evolution has intensified concern about head injuries.

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Gridiron footballRelated: Its rule changes established one of the family’s principal forms.