If the word "soccer" originated in England, why did it fall into disuse there and become dominant in the States? To answer that question, Szymanski counted the frequency with which the words "football" and soccer" appeared in American and British news outlets as far back as 1900.
What he found is fascinating: "Soccer" was a recognized term in Britain in the first half of the twentieth century, but it wasn't widely used until after World War II, when it was in vogue (and interchangeable with "football" and other phrases like "soccer football") for a couple decades, perhaps because of the influence of American troops stationed in Britain during the war and the allure of American culture in its aftermath. In the 1980s, however, Brits began rejecting the term, as soccer became a more popular sport in the United States.
In recent decades, "The penetration of the game into American culture, measured by the use of the name 'soccer,' has led to backlash against the use of the word in Britain, where it was once considered an innocuous alternative to the word 'football,'" Szymanski explains.
--Uri Friedman, The Atlantic, on linguistic backlash