The XV Commandments of Football

Swerve

Sort of.

In the 1860s and '70s, as we know, there were several competing "football" games, including the "buttociation" version and the "Rugby" version. Soccer was the first "football" game played by American universities, but after rugby was introduced to Harvard by visitors from McGill University in Canada, it so surpbutted soccer in popularity that soon "football" meant "rugby" in the US. But with the introduction of the scrimmage and the system of downs in the 1880s, the game played in the US diverged dramatically from the rugby played in Britain.

In the last decades of the 19th century, American football was the only football game widely played in the US, so the word "football" suited everyone there fine. But the sport at that time was so brutal, dozens of players were dying every season. Around 1905, colleges began to consider alternatives to American football, including "English rugby" (a retronym) and buttociation football. Because "football" was already entrenched in American language as the name of the American game, Americans wound up choosing the word "soccer" to refer to the buttociation game after its reintroduction in the 1900s.

I would suppose that "American football" is a term of British origin. In the US, it's always simply been called "football." By the time soccer started to compete with it, American football had been around for more than 20 years. Instead of changing "football" to "American football," the American simply took the British word "soccer" for the buttociation game.

MW