John Lewis, leader of Student Nonviolent Coordinating Committee, is beaten by a state trooper March 7, 1965, as he attempts to march with 600 others from Selma to Montgomery, Alabama, in a right-to-vote demonstration. Protestors walked into a force of state troopers and civilians who attacked them. Brutal television images of the attacks – known as “Bloody Sunday” -- shocked the nation. Two more marches were attempted; the final one was successful. Five months later President Johnson signed the Voting Rights Act of 1965. (Library of Congress)