" It has been said that the Civil War was “unnecessary” because slavery was already destined to end, probably within a few decades after the 1860 election. Yet this is mere dogma. The evidence points in the opposite direction. Slavery yielded ever more efficient production, in contrast to the free labor that tried (and failed) to compete with it, and the free labor that succeeded it. "

― , The Half Has Never Been Told: Slavery and the Making of American Capitalism