WE ARE NO longer sure what to call the black “underclass,” but we know by any name that it exists. Its features are universally familiar: weak connections with the world of productive work, little education, social and geographic isolation, family instability, high rates of crime, drug addiction, and dependency. But if we can agree on these defining features—and that all have been worsening over the past generation—there is no such agreement about their causes. Some stress racial discrimination, others government policy, economic change, or a distinctive “culture of poverty.” One of the few things common to the whole argument is a failure to begin at the beginning, to look at the history of urban black America for an explanation of its current situation and prospects. I hope here to clarify the debate through a look at that history, principally but not exclusively through the experience of a single city, Philadelphia.