"Cotton obsessed, Negro obsessed," Rupert Vance called it in 1935. "Nowhere but in the Mississippi Delta," he said, "are antebellum conditions so nearly preserved." This crescent of bottomlands between Memphis and Vicksburg, lined by the Yazoo and Mississippi rivers, remains in some ways what it was in 1860: a land of rich soil, wealthy planters, and desperate poverty--the blackest and poorest counties in all the South. And yet it is a cultural treasure...