Walter Camp is considered the 'founder' of American football. Camp was a great rugby player from Yale University who began to transform rules of rugby for a more 'modern' style of play, which eventually developed into the sport of football during the 1880's.. After spearheading the Intercollegiate Football Association (IFA) at the beginning of its creation, he helped create rules and positions like the quarterback, the line of scrimmage, and the scoring system we still use today!
The first college football game was played between Rutgers and Princeton in 1869, before Walter Camp's contributions to the game occurred. Rutgers won that game 6-4! The game more closely resembled a rugby game than a modern game of football, with 25 men on each side and large scrums, but as the years progressed and football became more popular, the sport developed into what it is today.
It was not until November of 1892 that the first professional football game was played between the Allegheny Athletic Association and the Pittsburgh Athletic Club. Allegheny's player William 'Pudge' Heffelfinger was paid $500 to play in the game, officially making him the first professional football player. Paying players was unheard of up until this point, but this rivalry game forced Pittsburgh and other teams to encourage better players to participate with monetary incentives, since every teams' main priority was to win.
These payments eventually became salaries as teams began generating revenue from games, and the rest is history!