Born a slave, Harriett Tubman became a famous "conductor" on the Underground Railroad, leading hundreds of slaves to freedom.

John Brown's failed attempt to loot the armory at Harper's Ferry sparks the beginning of abolition.

America is at the brink of a Civil War as cotton spreads west and threatens to expand slavery into new territories.

Lincoln develops and enacts a permanent plan to abolish slavery, in this clip from Season 1, "Saving the Union."