In April 1967, roughly 50,000 people packed into San Francisco’s Kezar Stadium in the largest protest march and rally the West Coast had ever seen.

The Spring Mobilization Committee to End the War in Vietnam, including a related protest in Manhattan’s Central Park, was notable for melding together disparate civil rights, labor, and counterculture movements in opposition to the war.

In the winter and early spring of 1967, two events helped to forge the coalition. In January, 30,000 beatniks and hippies gathered for the Human Be-In festival in Golden Gate Park that set the stage for the Summer of Love. Then on April 4, Dr. Martin Luther King Jr. shocked the country by forcefully denouncing the Vietnam War for the first time.

Paul Hofmann captured the scene at the San Francisco march on April 15 in a dispatch for the N.Y. Times. Black nationalists led a young, mostly white crowd, he wrote: “West Coast ‘hippie’ hair styles and attire — flowing ponchos, bell-bottom trousers and turtleneck sweaters — were conspicuous.”

At Kezar Stadium, filled nearly to capacity, activists, legislators, and union leaders spoke. The keynote was delivered by Coretta Scott King, wife of the civil rights leader, who linked the Vietnam War with deteriorating moral values at home. “Freedom and justice in America are bound together with freedom and justice in Vietnam,” she said.

The war didn’t end for another eight years. But historians have counted the 1967 protest as a catalyst for the efforts that would hasten its end. The spirit of the movement — “broad and diverse, peaceful and serious, direct and disorderly,” as one participant described it — has echoed in the decades of protests held in San Francisco to this day.

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Google Arts & Culture collected some fantastic photos from the Spring Mobilization in San Francisco by LIFE magazine’s Ralph Crane. See nearly 200 of those images here. (Note: Many are miscaptioned as taking place April 17.)

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