Inspired by the sit-ins of the Black Civil Rights Movement, the New York chapter of the Mattachine Society, led by Dick Leitsch and Craig Rodwell, staged a gay “sip-in” at the Julius Bar in New York City on April 21st of 1966 (3 years prior to Stonewall). When they were denied service, they sued the State Liquor Authority, and the courts ruled that it was not illegal to serve homosexuals in bars. However, as you rightly point out, both public opinion and the power of the NYPD, which was in league with the Mafia at that time, blunted the impact of the ruling.