Men and women, black and white, risked their lives to carve an elaborate network of escape routes out of slavery.
Marcus Garvey, a black nationalist leader from Jamaica, had great successes and failures before being jailed and deported from the US in 1927.
At the height of segregation, an unlikely alliance between a black medical genius and a white surgeon led to a pioneering medical breakthrough.
In the decade after the Civil War, former slaves sing their way into a nation's heart with spirituals, the religious anthems of slavery.
The story of the American civil rights movement is told through its powerful music -- the freedom songs that protesters sang on picket lines, in mass meetings, in police wagons, and in jail cells as they fought for justice and equality.
The women's suffrage movement won the right to vote when the 19th Amendment passed in 1920.
The international manhunt to catch the killer of Martin Luther King.