As noted in various places, including the online Merriam-Webster Collegiate Dictionary, soccer is a shortening and alteration of the term “association”. In the late-mid 1800’s, a split occurred among England’s public schools regarding the rules to be used to play “football”. Football, of course, had been played in various forms for centuries in England (usually a game between two towns who started kicking the ball somewhere between the towns in an attempt to get the ball to one town’s center square). The Italians had a similar game called calcio, and most cultures have had some sort of kick the ball game. But in the early 1800’s, England’s public schools decided that football, among other sports, when refined with some rules, was a classic game for teaching young men how to be young gentlemen through use of sport (a classic Victorian theme). I’ll omit references too numerous to mention; you can get this information from any decent encyclopedia.
When the schools played in house, they used their own rules. When they played among each other, they had to agree to a set of rules for the match. As time went by, attempts were made to come up with a uniform set of rules for playing among the various public schools. But a schism developed between those schools which thought that “football” should include the ability to pick the ball up and carry it, with an associated need to “tackle” the opponent by wrestling him to the ground, whereupon he was obligated to give up the ball, and those schools who thought “football” should be devoid of the use of hands, as well as any really physical play such as “hacking” the player with possession by kicking him in the shins, etc. The lead school in favor of playing pick the ball up and carry it football was Rugby, and it ended up leading its faction to the formation of the rules for Rugby football.
As for the other faction, the graduates of those schools ended up wanting to play the game as organized teams representing various athletic clubs. They met and formed a grouping of such clubs, known still as the Football Association (FA for short). The league they created was reported in the papers as “Association football”. Eventually, this was shortened to “Assoc.” football. The British, having a knack for slang terms of similar nature (J.R.R. Tolkein reported similar slang at Oxford during his days there), shortened this to “Asoccer” then simply “soccer”. Merriam-Webster gives the date of first recorded use as 1889.
So, as you see, the Americans have nothing to do with the term’s origin. Of course, it is used in America because it represents an easy way to differentiate the sport from the American form of football, which developed out of the Rugby game during the late 1800’s and early 1900’s. The Socceroos are indeed the Australian national soccer team, where they also have a version of football that is more popular than the game the rest of the world plays. By any name, of course, it is simply the most elegant and most fun game to play or watch… {ducking and running} 