History!
Football is a very old sport. Most people in other countries would think of soccer if an American said," Let's go play some football!" One day in 1823 a "kicking game" was in progress when the bell had just began to ring. William Webb Ellis caught the ball instead of moving back and waiting for it to land so he could kick it. For whatever reason he had, instead of marking the ball for at least one free kick, he took off and ran down in front of the goal. Today at Rugby School his name is immortalized as the person who basically created the rules of American Football, and the first person to take the ball in his arms.
Football has been played for almost a century. Field goals were the main kind of scoring. The forward pass was invented in the game because in 1905 president Roosevelt threatened to abolish the sport because too many people were dying from injuries from the sport. The father for the forward pass was Coach Pop Warner. Youth leagues are told about him and empowered by his greatness.