Samuel P. Hays was University Professor Emeritus of History at the University of Pittsburgh. He is the author of Wars in the Woods: The Rise of Ecological Forestry in America; Explorations in Environmental History; Conservation and the Gospel of Efficiency: The Progressive Conservation Movement, 1890-1920; and, with Barbara D. Hays, Beauty, Health, and Permanence: Environmental Politics in the United States, 1955-1985.