One of the best-known differences between British and American English is the fact that the sport known as football in Great Britain is usually called soccer in the United States. Because the sport originated in England, it is often assumed that soccer is an Americanism. In fact, the word is thoroughly British in origin.

In the U.S., a different sport was born out of mixing rugby and association football together to create gridiron football. Britannica reported that most people began calling the second sport “football” and, in order to tell the two sports apart, the American association-football players started referring to their sport as “soccer,” by 1945.

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.