Conventional wisdom tells us that marriage was illegal for African Americans during the antebellum era, and that if people married at all, their vows were tenuous ones: "until death or distance do us part." It is an impression that imbues beliefs about black families to this day. But it's a perception primarily based on documents produced by abolitionists, the state, or other partisans. It doesn't tell the whole story. Drawing on a trove of...