In 1964, Richard Muller, a 20-year-old graduate student with neat-cropped hair, walked into Sproul Hall at the University of California, Berkeley, and joined a mass protest of unprecedented scale. The activists, a few thousand strong, demanded that the university lift a ban on free speech and ease restrictions on academic freedom, while outside on the steps a young folk-singer called Joan Baez led supporters in a chorus of We Shall Overcome. The sit-in ended two days later when police stormed the building in the early hours and arrested hundreds of students. Muller was thrown into Oakland jail. The heavy-handedness sparked further unrest and, a month later, the university administration backed down. The protest was a pivotal moment for the civil liberties movement and marked Berkeley as a haven of free thinking and fierce independence.