American football, also known as gridiron football, is a variation of the game of football that developed from rugby and association football in England. It differs from football primarily in that players are permitted to touch, throw and carry the ball with their hands, and it differs from rugby in that each side is permitted to control the ball while switching possessions. It was invented in North America, particularly in the United States, where it eventually rose to become the most popular spectator sport in the nation. The game is played with 11 players on each side.
Rugby regulations were first broken by Harvard. Harvard chose to “heel it out,” or kick the ball back to a teammate, instead of the usual method of putting the ball in play, in which players from both teams gathered around the ball in a “scrummage,” or “scrum,” aiming to kick it forward through the crowd of players. Walter Camp, who was hailed as the “Father of American Football” even in his lifetime, was primarily responsible for continuing the conversion of English rugby into American football.
The implementation of a rule banning projecting nails or iron plates in shoes and any metal object on the player’s person in 1894 is a good example of the early football spirit. Over the years, laws defining the limits between acceptable and unacceptable violence have been continuously updated, sometimes in reaction to periods of increased concern over fatalities and injuries. From two in 1873 to seven in 1983, the number of officials increased to offer greater safety.
While professional football struggled for respectability, college football was thriving. The American Professional Football Association, which included the teams that would eventually become the National Football League (NFL), was established in 1920, with Jim Thorpe serving as its nominal president. Since 1892, former collegiate athletes have competed for pay, first for athletic clubs in western Pennsylvania and then for teams that were founded in primarily small communities in Pennsylvania, Ohio, and Illinois.