Why is football called soccer in America?

Dear Word Detective: I would be interested to learn the origins of the word "soccer." As a Brit currently living in the US, I am often dismayed to hear the term used to describe a sport that I, and many of my countrymen, have always known as "football." Is usage of the word "soccer" within the US simply a way of distinguishing the "beautiful game" from the altogether less appropriately-named sport of American Football (which, to my understanding, is played almost exclusively with one's hands)? -- Pete Collins, via the internet.

You know, as much as I like this question, I can't quite get over the feeling that I'm being set up. After all, I live about 35 miles from Columbus, Ohio, home of the OSU Buckeyes football team, and people around here are bananas (to put it politely) about football. Skeptics on the subject of Buckeye supremacy have, in fact, been known to disappear without a trace along with their household pets. But what the heck, since I've never had the sense God gave cole slaw, I'll stick my neck out and agree that "soccer" is a far more intelligent, skillful and interesting game.

It's true that the game known as "football" in most of the world (not just the UK) is known as "soccer" in the US, but we didn't just pull the word out of the air so that we could call our quasi-gladiatorial extravaganzas "football." In fact, you Brits actually invented the word. "Soccer," when it first appeared in the 1890s, was spelled "socca," which was short for "association" or "association football," meaning football played according to the rules laid down by the British Football Association. It was also called "socker" until the current form "soccer" appeared around 1895.

The "er" suffix of "soccer," incidentally, was often used in late 19th and early 20th century slang, and can also be found in the transformation of the name of the British game "rugby" (named after the Rugby School in England) into the popular term "rugger." Rugby, incidentally, is a sport similar to American football, but played without the helmets and elaborate padding used in American stadiums.

from The Word Detective's website