On June 27, 1970, one year after the historic Stonewall uprising in New York City, a small group of LGBTQ people marched down Polk Street, the most prominent queer neighborhood in San Francisco, protesting for gay rights. Now, 50 years on, those small congregations have increased by the thousands, attracting activists from all over the world. In this online slideshow, over 50 photographs depict moments from the San Francisco marches, summoning up the anger, joy, and creativity that has characterized the gay rights movement. —E.C.