Boyle spends the book's prologue setting up the social conditions in America's Midwestern and Northeastern cities following the Great Migration. This pattern of movement brought more than a million southern-born blacks from south of the Mason-Dixon line to the North between 1916 and 1930. Job opportunities in northern factories, made vacant by the exodus of white male workers for the American war effort, drew Southern blacks north via the train lines built after the Civil War. Ossian Sweet is one such migrant, drawn northward by the opportunity to attend college in Ohio. This influx of black populations in mostly white towns and cities brings with it social unrest and, sometimes, violence fueled "by fear of moral decay" (6). Native-born whites felt threatened by the numbers of black migrants alongside whom they did not want to work or live. Racism takes on an official form via restrictions on hiring and renting or selling property to black migrants. In Detroit, blacks are relegated to living in Black Bottom, crammed into "tiny apartments, which they rented at exorbitant rates" (11). Though not legally sanctioned, these practices became standard; fear of moral decay reaches a fevered pitch by the time Ossian and his wife, Gladys buy their home on all-white Garland Avenue.