It is the "heartland," the home of the average--middle--American. Yet the definition of the Middle West, that most amorphous of regions, is elusive and changing. In historical, cultural, political, literary, and artistic terms the region is variously drawn. It is alternately praised as a pastoral oasis and damned as a cultural backwater, fostering wholesome pragmatism and crass materialism, home to people at once resilient and embittered, hardworking...