A great many books have been written about Harlem, but for social history none has surpassed Gilbert Osofsky's account of how a pleasant, pastoral upper-middle-class suburb of Manhattan turned into an appalling black slum within forty years. Mr. Osofsky sets his chronicle against the background of pre-Harlem black life in New York City and in the context of the radical changes in race relations in America in the late nineteenth and early twentieth...