The Smithsonian Institution’s River Basin Surveys and the Interagency Archeological Salvage Program were the most ambitious archaeological projects ever undertaken in the United States. Administered by the National Park Service from 1945–1969, the programs had profound effects—methodological, theoretical, and historical—on American archaeology, many of which are still being felt today. They stimulated the public’s interest in heritage preservation, led to the passage of the National Historic Preservation Act, served as the model for rescue archaeology in other countries, and helped launch the “New Archaeology.” This book examines the impacts of these two programs on the development of American archaeology.