Did you know the first known instance of anyone making the force/fourth pun came in 1979 — on May 4, obviously — when Margaret Thatcher became the UK's first female prime minister?
To celebrate the victory, Thatcher's party backers took out a newspaper ad with the tongue-in-cheek text, "May The Fourth Be With You, Maggie. Congratulations."
And while Star Wars fans have long since made this pun on May 4, the idea of the date actually becoming a holiday wouldn't solidify until 2011.