Brits coined the term soccer in the late 1800s to refer to Association Football, the sport we now know as soccer/football. "Soccer" was picked as a way to differentiate from another kind of football—Rugby Football. For a similar reason, "soccer" became the favored term in America, a way to differentiate against Gridiron Football.

"Association football" became "soccer." After these two sports spread across the Atlantic, Americans invented their own variant of the game that they simply called "football" in the early 1900s. "Association football" became "soccer" in America, and what was called "gridiron" in Britain became simply "football" in America.

So, why do Americans call it soccer? The answer lies in the history of the sport and the evolution of language. Soccer originated in England, where the sport we know as soccer today was referred to as association football.