Bloody Sunday: the march across the Edmund Pettus Bridge

On March 7, 1965, some 600 voting-rights marchers set out from Brown Chapel AME Church in Selma, Alabama, to walk to the state capital in Montgomery — demanding the ballot after the police killing of activist Jimmie Lee Jackson. As they crossed the Edmund Pettus Bridge, named for a Confederate general and Klan leader, Alabama state troopers and a sheriff's posse attacked them with clubs, tear gas, and bullwhips. John Lewis's skull was fractured; the organizer Amelia Boynton was beaten unconscious, and the photograph of her body became one of the era's defining images.

Television carried the scenes of "Bloody Sunday" into living rooms across the country, and the nation recoiled. Within days Martin Luther King Jr. led a symbolic second crossing; then, under federal protection, thousands completed the 54-mile march to Montgomery on March 21–25. The outrage drove Congress to pass the Voting Rights Act of 1965 within months — the most effective civil rights law in American history, and the fulfillment, at last, of the Fifteenth Amendment's promise.