Over the last forty years, the human landscape of the United States has been fundamentally transformed. The metamorphosis is partially visible in the ascendance of glittering, coastal hubs for finance, infotech, and the so-called creative class. But this is only the tip of an economic iceberg, the bulk of which lies in the darkness of the declining heartland or on the dimly lit fringe of sprawling cities. This is America's hinterland, populated by...