When was gridiron changed to the name football?

Answer 1

American football, sometimes called Gridiron, has always been called "Football" in the United States since it was invented. This is why Americans refer to Association football as "soccer", even though the English (who invented the word) generally stopped using that word long ago. The name "Gridiron" comes from a name used to describe or refer to the American football field of play, so-named because of the grid-like jail-bar pattern the lines make.