According to William Cronon in Nature's Metropolis, how did the rise of Chicago begin to conquer the vast mid-section of the continent?
Cronon argues that Chicago opened the Great Plains to settlement by "second nature," the "improvement" of natural resources available. Because of it's location and the effort and capital invested in the enterprise, Chicago become a hub through which settlement flowed. It provided markets for agricultural goods and timber, transportation infrastructure in the form of railroads, processing plants for meats, and credit markets through which capital flowed. The crucial point is that this is, to say the least, not necessarily a positive development. Chicago both provided a template for and a base for the ecological annihilation of the Great Plains. It also was the space in which the commodification of living things, especially livestock, became a reality. Eventually, the people who moved onto the plains perceived Chicago as a place where parasitical bankers and magnates grew rich at their expense. Cronon argues that without the city, the frontier would not have been possible, a inversion of Frederick Jackson Turner's "frontier thesis." City and country were tied together inextricably.