Who thought of football first?

Answer 1

Primitive forms of Rugby, then all covered by the name "football", were being played in the USA as far back as the 1840s, at Harvard, Yale and Princeton, stemming partly from Americans who had been educated in English schools.

American football resulted from several major divergences from rugby football, most notably the rule changes instituted by Walter Camp, considered the "Father of American Football". Among these important changes were the introduction of the line of scrimmage and of down-and-distance rules.