Donald Worster is the Hall Distinguished Professor of American History at the University of Kansas. His current research focuses on the shift in America from a culture of abundance to one of scarcity. He is the author of a number of books, including Rivers of Empire: Water, Aridity, and the Growth of the American West (Pantheon Books, 1985) and The Wealth of Nature: Environmental History and the Ecological Imagination (Oxford University Press, 1993).