Book excerpt: In the middle years of the Great Depression, Erskine Caldwell and photographer Margaret Bourke-White spent eighteen months traveling across the back roads of the Deep South--from South Carolina to Arkansas--to document the living conditions of the sharecropper. Their collaboration resulted in You Have Seen Their Faces, a graphic portrayal of America's desperately poor rural underclass. First published in 1937, it is a classic comparable to Jacob Riis's How the Other Half Lives, and James Agee and Walker Evans's Let Us Now Praise Famous Men, which it preceded by more than three years. Caldwell lets the poor speak for themselves. Supported by his commentary, they tell how the tenant system exploited whites and blacks alike and fostered animosity between them. Bourke-White, who sometimes waited hours for the right moment, captures her subjects in the shacks where they lived, the depleted fields where they plowed, and the churches where they worshipped.