It's called Woodstock Festival. Ironically, the event didn't happen in Woodstock. Yes, the town of Woodstock refused to host the event! The event was held in Bethel, in Sullivan County, it's town Southwest of Woodstock, New York (which is why it was called Woodstock).
Initially publicized as "An Aquarian Exposition: Three Days of Peace and Music", the festival was originally planned to be in Wallkill, New York. However the residents of the town strongly opposed to the idea of having hundreds of hippies in their area. Likewise, the town of Woodstock also did not approve of having the concert in their area.
Thankfully, despite the short notice, the owner of the dairy farm 50 miles from Woodstock agreed to have the event on his property.
Meet Max Yasgur and his wife. Woodstock wouldn't have happened if not for this man. Yasgur was the owner of the dairy farm where the iconic festival took place. Well it didn't technically take place on his dairy farm, but rather on one of his farm's fields.
Dairy farmer Max Yasgur came to the rescue at the last minute when promoters thought that all hope was lost. Yasgur leased some portions of his 600-acre farm to Woodstock Ventures. Of course just as in other towns, the residents of Bethel also opposed to the point that they were even thinking of organizing a boycott from buying products of Yasgur's farm. But there really wasn't much that the residents could do since New York governor Nelson Rockefeller had approved such event.
Though hippies and music lovers have such high regard for Yasgur and had such high respect for him, it wasn't the same for his neighbors. After the festival, his neighbors sued him for property damage left by the crowd. Likewise, his own property suffered the most damage. Thankfully, he was given compensation for such.