On the afternoon of April 21, 1966, a bar crawl in New York’s West Village leads to an important early moment in the gay liberation movement. In what will be dubbed the “Sip-In,” Dick Leitsch, Craig Rodwell and John Timmons publicly identify themselves as gay and demand to be served anyway, challenging the unofficial but widespread practice of banning gay customers from bars.

Although the gay community in New York grew and established numerous clandestine hubs over the course of the 1950s and '60s, they were still met with open contempt at most bars, restaurants, and nightclubs in the city. Gay men were often accused of “disorderly conduct” simply for being gay and thrown out of bars even though there was no law against homosexuality or serving gays. These were acts of bigotry, but also self-preservation, as the NYPD routinely raided and shut down bars where gays were known to congregate. It was not uncommon for bars to put up signs with messages like “If you are gay, please stay away,” or the slightly subtler “Patrons Must Face the Bar While Drinking,” a coded warning against men trying to pick up other men.

Leitsch, Rodwell, and Timmons—later joined by Randy Wicker—were members of the Mattachine Society, a group that tried to break the taboo around homosexuality and present themselves as clean-cut model citizens to combat homophobia and carve out a place in the public sphere for openly gay men. Borrowing an idea from the civil rights movement, they decided to sit down at various bars in Lower Manhattan, announce that they were gay and refuse to leave without being served. The trio was kicked out of the first bar before they arrived—a reporter they had tipped off beat them to the bar and spilled the beans to the bartender, who closed his bar rather than serve them. The group proceeded to two more bars, telling their servers they were gay, and each instance ended with a discussion with the manager and free drinks for the activists. “I’m starting to feel drunk,” Timmons recalled telling his friends. “We better get this done already.”

They finally made their stand at Julius’ Bar, a spot popular with the gay community. The bartender put a glass down in front of Leitsch as he approached the bar, only to place his hand over it after Leitsch announced that he was gay. A newspaper photographer captured the moment, and the Sip-In became legend. Some accounts of the Sip-In hold that the bartender at Julius’ was playing along with the Mattachine in order to help them attract publicity, while others claim that Julius’, though usually gay-friendly, denied the men their drinks because it had been raided by the police just a few days before.

Although its legacy would be dwarfed by the Stonewall Riots, which began in the same neighborhood three years later, the Sip-In did cause a stir. News of the event prompted an official announcement from the chairman of the New York State Liquor authority, affirming that there was nothing in state law about denying service to gays, and a ruling from New York’s Commission on Human Rights that one could not be denied service simply for being homosexual. Across the river in New Jersey, the Mattachine began suing bar owners who denied them service the following year, winning a state Supreme Court ruling that, while labelling gays “unfortunates,” held that “their status does not make them criminals or outlaws.”