Americans today find themselves mired in an era of uncertainty and frustration. The nation's safety net is pulling apart under its own weight; political compromise is viewed as a form of defeat; and our faith in the enduring concept of American exceptionalism appears increasingly outdated.

But the American Age may not be ending. In The Vanishing Neighbor, Marc J. Dunkelman identifies an epochal shift in the structure of American life--a shift unnoticed by many. Routines that once put doctors and lawyers in touch with grocers and plumbers--interactions that encouraged debate and...