Gunsang: P.S. It is used for other sports which you carry an egg around not just in America, but other commonwealth countries such as Canada and Australia.
gameon: In Australia they have their own game called Aussie rules football.
In Ireland they have the Gaelic games football:
http://en.wikipedia.org/wiki/National_Football_League_%28Ireland%29 But they also recognise that english football is football. Their own "football" are spin offs between football and rugby.
Canadian Football is a spin-off of American Football, Australians and Canadians (at least the ones I've talked to) refer to Association Football as Soccer, and I sincerely hope the vast majority of Americans know that in most countries the term "football" refers to Association Football. Also, I am well aware that their sports are rugby based.
DukeNukemForever: I know a similar story about how football developed from rugby. Fine people wanted a cleaner game and forbid to play with hands, it was only allowed to play the ball with the foot. Don't know if that's true, about that topic there are different stories in circulation.
I thought Rugby was developed after Association Football, but I could be wrong.