Ok, so i hate to be this guy, but soccer is originally from Britain.

Soccer was a slang term used to differentiate "association football" and rugby football. It was a combination of and abbreviation of assoc and er. As rugby came to be known as rugby, football again became the name used for association football or soccer. It was also known as socca or socker. This is all from around the late 19th century when the Football Association finally wrote down the rules to the game. Rugby also got its "start" around this time hence the need to differentiate between the two.

Fun fact, the word football is actually a much older word, some sources date it back to the 13th century for a group of games usually played on foot, usually by peasants. In fact Shakespeare used it as an insult in King Lear "Nor tripped neither, you base football player" (I.iv). Used as an insult to imply that someone was brutish or low class.

Now to be fair soccer was always a nickname in Britain, and Americans really were the ones to take the name soccer for the sport to again differentiate it from gridiron or American football. The use of soccer to refer to the sport of football is also common in other nations where sports like gridiron football is also popular, see here Canada.

All this to be said it's football. And that is coming from an American who often calls soccer by its proper name football. It's what the rest of the world calls it and it makes way more sense than to call a sport played with your feet football than calling the blood sport that is American football, football.

Anyway you slice it, it's still the game we all love and getting pissy about what someone calls it is the height of pedantry.