On a quiet Sunday morning in September 1963, a bomb blew open the Sixteenth Street Baptist Church in Birmingham, Alabama. Four young African-American girls who were preparing for the worship service died in the blast. The attack was the work of the Ku Klux Klan, a shadowy racist organization that for decades waged a violent campaign of terror against people working for racial equality. The devastating bombing gave momentum to the civil rights movement, leading to the passage of important federal civil rights laws.