On March 21, 1965, roughly 8,000 marchers departed Selma, Alabama, crossing the Edmund Pettus Bridge under federal protection after President Johnson deployed National Guard troops. The march came two weeks after 'Bloody Sunday,' when state troopers had brutally beaten peaceful demonstrators attempting the same route. The successful five-day march to the state capitol in Montgomery built momentum that helped secure passage of the Voting Rights Act of 1965 just months later.
Two weeks earlier, on March 7, 1965, some 600 marchers attempting this same route had been met at the Edmund Pettus Bridge by Alabama state troopers who charged into the crowd with billy clubs and tear gas, an assault broadcast nationally as 'Bloody Sunday.' A second attempt on March 9 turned back after King, wary of a federal court order, led marchers only to the bridge before retreating.
After federal judge Frank Johnson ruled the march could proceed and President Lyndon Johnson federalized the Alabama National Guard to protect the marchers, roughly 8,000 people, Black and white, set out from Selma on March 21 under the protection of soldiers, FBI agents, and federal marshals. The march stretched over five days and 54 miles along U.S. Route 80, with numbers thinning to around 300 core marchers permitted on the narrower two-lane stretch by court order, before swelling again to some 25,000 as they reached Montgomery.
King delivered his 'How Long, Not Long' speech on the capitol steps on March 25. The moral force of the march, combined with the murder of activist Viola Liuzzo on the return drive that same night, helped push Congress to pass the Voting Rights Act, signed into law by Johnson on August 6, 1965, outlawing the discriminatory practices that had kept Black southerners from the polls for generations.