Shaped millions of years ago by the receding waters of a once great glacier, the land surrounding the confluence of the Allegheny, Monongahela, and Ohio rivers has supported communities of humans for millennia. In the past four centuries, however, it has been transformed utterly and many times over by the people who call it home. In this brief, lyrical, and idiosyncratic new book, Ed Simon follows the story of America's furnace through a series of interconnected segments.