Influenced by European Romanticism, Americans have thought and written about their relationship to the natural world at least since the beginning of the nineteenth century. The earliest works of environmental history-concerning the United States at least-were written primarily in the 1930s and 1940s and focused on the West.2 But American environmental history as a distinct field of study-possessing a wide range of nuance and topic-did not take shape until the late 1960s with the emergence of the modem environmental movement. Although it drew enthusiastic support from college students and others caught up in the political and social turmoil of the 1960s, the modem environmental movement was rooted more deeply in the American experience. Attracting major support from the middle and upper-middle classes, and bolstered by the maturing of ecological science, it functioned politically as a coalition of groups with a variety of interests, including natural-environment issues such as outdoor recreation, wildlands, and open space, and in concerns over public health and environmental pollution.