The regional history one writes depends, to a large degree, on the region one defines and studies. I have defined the “Great West,” a region that developed across the Mississippi River valley in the middle of the nineteenth century, primarily as an economic and urban system. The patterns of settlement, urbanization, market production and consumption, and transportation and information flows were all shaped by the intersection of behavior shaped by previous experiences along the Ohio River and in the East with the environment, topography, and climate along the Mississippi River north of St. Louis. Early settlers, as we have seen, clustered along the rivers and moved slowly from south to north, and from the river into the interior, across the area between 1820 and 1850.

The exception to this was the early settlement of the Lead Region in the late 1820s and early 1830s, far ahead of the line of first settlement downriver. This island population producing a much needed resource provided the original stimulus for the economic development of the valley. By the late 1820s, Galena, Illinois, had become the primary entrepôt of the Lead Region, and a distant outpost of wholesalers, steamboatmen, and bankers in St. Louis, Missouri. This outpost economy, connected by a long-distance line of steamboats, established the foundation of the valley's transportation and, hence, its economic system. In the following two decades, as settlement moved north along the river and scores of towns were founded, a few of which became local depots, the steamboat system filled in and farmers on both sides of the river began sending enormous amounts of produce to the entrepôt in St. Louis.