The October-November 1952 issue of Mad, published in August, was the beginning of a great American tradition. EC, famous up to that time for horror comics, moved in a new direction. Published by Bill Gaines and edited by Harvey Kurtzman, Mad introduced sharp satire (Humor in a Jugular Vein) to comic books.
Mad became a magazine in 1955. Legend said it was because of the growing controversy about comic books, but it was done to satisfy Kurtzman's ambition.
I read Mad for many years and it certainly influenced my sense of humor. I know some movies better through reading the Mad parodies rather than seeing the movies themselves.