The World of Our Dreams: Agricultural Explorers and the Promise of American Science, 1890-194

Amidst global fears about nutrition, food security, and rising farm costs, concerns about crop diversity are one of the most pressing environmental issues today. Despite emerging research on declining crop diversity, its origins in the late nineteenth and early twentieth centuries have been contested. Historians of science have argued that research should focus on the emergence of commercial plant breeding, while agricultural historians have long focused on the ways mechanical developments have contributed to genetically uniform monocultures. Much of this scholarship understates the impact of germplasm (living genetic resources) introduction on plant breeding and crop production. Relatively little is known about the role of USDA scientists and bureaucrats in twentieth century agricultural development. This dissertation examines the work of plant introduction and its scientific and ecological legacy. From the 1890s through the first half of the twentieth century, the USDA's scientific "agricultural explorers" transformed farming by providing germplasm for plant breeders and supplying the biological means for developing new crops. This dissertation recovers their role through a survey of the letters, memoirs, and field notes of plant explorers and agronomists while rooting their observations in a range of historic scientific literature such as USDA publications, scientific periodicals, and journals. It argues that while plant explorers delivered unprecedented genetic diversity to the United States, their work ultimately contributed to the rise of genetic uniformity across farming landscapes. Eschewing agrobiodiversity, federal biologists promoted models that risked long-term plant diversity for the sake of short-term economic stability. Without a history of plant introduction, we remain ill-informed about the crisis of crop diversity and fail to provide a historical understanding of why our farm landscapes operate in their current form.