The Woodstock Music and Art Fair, "An Aquarian Exposition," opened on this day in 1969 at Max Yasgur's dairy farm in upstate New York — 54 years ago. Promoters expected the music festival, modeled after the famous Monterey Pop Festival, to attract up to 200,000 for the weekend. Instead, nearly a half a million people converged on the concert site. The promoters soon realized that they could not control access to the site and opened it up to all comers free of charge.