The London Evening News printed a half page that said “May The Fourth Be WIth You, Maggie. Congratulations.”
Star Wars had been released two years earlier, and its cultural impact was enough that the pun on “May The Force Be With You”, one of the movie’s catchphrases, was universal enough to make sense in a British print ad.
It wasn’t until 2011, though, that fans began to co-opt the day as a celebration.
Source: Snapchat’s Discover Section – MTV Bubble