Harry Hay, born April 7th, 1912 established the Mattachine Society in 1950! A full nineteen years before Stonewall.
(BTW, technically, Stonewall was an uprising, not a riot.)
Harry Hay was a Marxist and active supporter of Native American rights which inspired Hay to co-found the Radial Faeries with his long term boyfriend John Burnside.
He was vocally anti-assimilation, with quotes like;
And;
Even the “Mattachine” name is subversive, according to the opening credits of the documentary of Harry Hay’s life produced by Eric Slade:
Harry Hay was a pretty cool faerie! With the 50th Anniversary of the Stonewall Uprising coming up, it would do us all some good to remember the anti-assimilationist, anti-commercialism that was at the heart of the gay rights movement. Harry Hay died on October 24, 2002.
Enjoy this well deserved blow job – on us!

Homosexuals ARE different!
Also, here is a list of a bunch of political action that pre-dates the Stonewall Uprising, including the little known Cooper Do-Nuts Uprising in 1959 and the semi-famous Compton’s Cafeteria Uprising in 1966.
Especially fond of this pic: