Marchers cross the Alabama river on the Edmund Pettus Bridge at Selma on March 21, 1965. The civil rights marchers, eight abreast, are led by Dr. Martin Luther King Jr. This is the start of their five day, 50-mile march to the State Capitol of Montgomery, Alabama. They are fighting for voter registration rights for blacks, who are discouraged from registering to vote, particularly in small towns in the south. (AP Photo)