On 1 December 1955, Rosa Parks — a 42-year-old seamstress and NAACP secretary — refused to surrender her seat to a white passenger on a Montgomery, Alabama city bus, as required by the city's segregation ordinance. She was arrested and charged with violating the segregation law.
Her arrest ignited the Montgomery Bus Boycott, coordinated by the Montgomery Improvement Association and led by a 26-year-old Baptist minister named Martin Luther King Jr. For 381 days, the city's Black residents — who made up 75% of the bus ridership — walked, carpooled, and organised rather than ride the buses. The boycott ended on 20 December 1956 with a Supreme Court ruling (*Browder v. Gayle*) that bus segregation was unconstitutional.
Parks's act was not spontaneous — she was a trained civil rights activist, and her arrest was strategically chosen to mount a legal challenge. It catalysed the Civil Rights Movement, elevated King to national leadership, and demonstrated that organised nonviolent resistance could defeat institutionalised segregation.