Understanding the origins, justification, and economy of slavery is crucial to understanding American society, the coming of the Civil War, and the effect of that war on American culture and identity. Chattel slavery has existed throughout world history, and U.S. slavery grew out of older European and African forms of enslavement. Yet slavery in the United States was distinctive for two important reasons. First, there have been relatively few true slave societies (as opposed to societies with slaves) in world history: ancient Greece, ancient Rome, Brazil, the Caribbean and the United States. Second, among these only the last three were based on race. Thus the slave system in place in the United States from about the mid-seventeenth century until the war's end was one of only three societies in world history to be a race-based slave society.

How Slavery Was Justified

Slavery began in what would become...