Since 1900 Americans attitudes toward the world they inhabit have changed as greatly as their own way of life. As their pace quickened, as they left the rural world of their pre-industrial ancestors and moved to urban areas, Americans became enamored of the natural world, if only as a myth. In Saving the Planet, Hal Rothman explains why Americans now see in the environment a salvation of themselves and their society, and a respite from the pressures of modern life. Mr. Rothman traces the origins of environmentalism to the diverse reform currents of the 1890s and the conservation movement of...