American football, or American soccer, is derived from English rugby and is a form of rugby. In the mid-nineteenth century, a game similar to soccer was often played in the eastern United States, in which players scored points by kicking the ball over the opposing team's goal line. Teams of up to 30 players, and sometimes more, competed. Because of this American football initially only allowed to kick, so named FOOTBALL, that is, the meaning of soccer, used to this day, now some people still call this football American soccer (NFL). After the rugby ball was introduced to the United States, people changed the rules, including the change to be able to pass the ball forward. Players are required to wear protective clothing and helmets because there is often a physical collision with opposing players.

American soccer is a popular competitive sport in the United States. The goal of the sport is to bring the ball into the opponent's "touchdown zone" to score a touchdown, mainly by holding or throwing the ball. There are a variety of ways to score, including holding the ball over the end zone, throwing the ball to a teammate behind the end zone, or kicking the ball straight down the ground through the middle of two goalposts, also known as a field goal. The team with the most points at the end of the game wins.

Development of the game

American soccer and (English) soccer both evolved from various forms of footy popularized in the United Kingdom in the mid-nineteenth century. Of these, American soccer evolved directly from rugby in England.

Rugby was originally introduced to North America by the British Army when it was played at McGill University in Montreal, Canada. This is where the Canadian and American styles of soccer began to evolve.

Colleges in the United States led to the growth of American soccer. The first intercollegiate soccer game was played on November 6, 1869, between Rutgers University in New Jersey and Princeton University. Rutgers beat Princeton six to four, although the football-like game, which pitted 25 men against each other, bore little resemblance to modern American soccer.

The modern form of American soccer was developed in a three-game series between Harvard and McGill University in Montreal in 1874, with McGill playing rugby-style soccer and Harvard playing the Boston style, which is more akin to (English) soccer. Since there was no standardized rules, the two teams took turns playing with their own rules to be fair. Harvard's players liked the rugby style of running with the ball, and in 1875 convinced Yale to adopt the rugby style for their teams, and in 1876 Yale, Harvard, Princeton, and Columbia formed the Intercollegiate Football Association with the rugby style, but with a slightly modified scoring style. The scoring pattern was slightly modified.

In 1880, Walter Camp introduced the offensive and defensive lines to replace the football juxtaposition. The rule was that each side had 11 players, with 4 backs and 7 forwards, with substitutes. The game is played in 4 quarters of 15 minutes each, with a 2-minute break between the 1st and 2nd quarters and between the 3rd and 4th quarters, and a 20-minute break between the 2nd and 3rd quarters. The game is played on a field 120 yards long and 160 feet wide. There is a goal line 10 yards in front of each end line, the distance between the two goal lines is 100 yards, the goal is set in the center of the end line, and the system is the same as that of English rugby. American football ball is slightly smaller than the English rugby, the ball is 11 to 11.5 inches long, the long axis of the ellipse is 28 to 28.5 inches, the short axis is 21.25 to 21.5 inches, weighing 14 to 15 British two. In the game, the player with the ball to the opponent's goal in front of the scoring area touchdown scores 6 points; also can kick another time to set the ball, such as kicking the set ball over the crossbar of the opponent's goal, but also another 1 point, all other cases of shots on goal scores 3 points; the player with the ball by the defending side squeezed out of the end line, the defending side scores 2 points. When the player with the ball is dropped four times by the opponent and fails to advance 10 yards, the kickoff is changed to a side-by-side kickoff.

In 1882, the limited-opportunity offense was introduced to stop Princeton and Yale from using the delaying tactic of "possessing the ball without attempting to score."

In 1883, the number of players on the field was reduced to eleven at Kemp's suggestion, and Kemp standardized on a seven-man offensive line and a quarterback, Kemp also standardized a seven-man offensive line, a quarterback, two halfbacks and a fullback.

On September 3, 1895, the first professional soccer game was played in Latrobe, Pennsylvania, between the Latrobe YMCA and the Jeannette Athletic Club. Latrobe won the game twelve to nothing.

By the 1890s, interlocking formations such as the flying wedge and teammates dragging the player in control of the ball forward made American soccer dangerous. Despite restrictions on flying wedge formations and other precautions, eighteen players died in 1905 from injuries sustained during the game. Theodore Roosevelt, then President of the United States, told the university that the game must be played. Theodore Roosevelt, then President of the United States, told universities that the game must be made safer. To force universities to take his concerns seriously, Roosevelt threatened to force Congress to pass a law making it a federal offense to play soccer.