Twelve Years a Slave is a memoir of a black man who was born free in New York state but kidnapped, sold into slavery and kept in bondage for 12 years in Louisiana before the American Civil War. He provided details of slave markets in Washington, DC, as well as describing at length cotton cultivation on major plantations in Louisiana.
Published soon after Harriet Beecher Stowe's novel, Uncle Tom's Cabin, Northup's book sold 30,000 copies and was considered a bestseller. It went through several editions in the nineteenth century. Supporting Stowe's fictional narrative in detail, Northup’s first-hand account of his twelve years of bondage proved another bombshell in the national political debate over slavery leading up to the Civil War, drawing endorsements from major Northern newspapers, anti-slavery organizations, and evangelical groups.