Tear gas fumes fill the air as state troopers, ordered by Gov. George Wallace, break up a demonstration march in Selma, Ala., on what is known as Bloody Sunday on March 7, 1965. As several hundred marchers crossed the Edmund Pettus Bridge to begin their protest march to Montgomery, state troopers violently assaulted the crowd with clubs and whips. A shocked nation watched the police brutality on television and demanded that Washington intervene and protect voter registration rights for blacks. (AP Photo)