In 1969, police raids of gay bars in Manhattan followed a template. Officers would pour in, threatening and beating bar staff and clientele. Patrons would pour out, lining up on the street so police could arrest them. But when police raided the Stonewall Inn in the early morning hours of June 28, 1969, things didn’t go as expected. Patrons and onlookers fought back—and the days-long melee that ensued, characterized then as a riot and now known as the Stonewall Rebellion, helped spark the modern LGBTQ civil rights movement.

Each June, Pride Month honors the history of Stonewall with parades and events. This year is the fifth anniversary of the Supreme Court’s landmark ruling on June 26, 2015, guaranteeing same-sex couples the right to marry.

Before these gains, however, LGBTQ people had long been subject to social sanction and legal harassment for their sexual orientation, which had been criminalized on the pretexts of religion and morality. By the 1960s, homosexuality was clinically classified as a mental disorder, and most municipalities in the United States had discriminatory laws that forbade same-sex relationships and denied basic rights to anyone suspected of being gay. Altough some gay rights groups had begun to protest this treatment publicly, many LGBTQ people led their lives in secret.