The Louisiana Purchase marked unrestricted American settlement of Missouri. Emigrants followed the Ohio, Mississippi, and Missouri rivers and the few overland routes, and most came from the upper South and lower Middle West. Many Scots-Irish were among this wave of settlement, coming mainly from Kentucky, Tennessee, and Virginia. Fewer came from other southern states, Ohio, Indiana, and Illinois.
Local settlement patterns give a better understanding of Missouri settlers. Families, their relatives, and neighbors moved as groups to new lands in Missouri. Examples include a cluster of settlers from Georgia in central Cape Girardeau County and Maryland Catholics in Perry County who settled the Barrens. One cluster of German and their Scots-Irish neighbors from North Carolina settled in Cape Girardeau County and to the west starting in 1800. Relatives and neighbors of these emigrants continued to arrive until 1860.
Today we refer to this phenomenon as chain migration, in that new emigrants find good conditions, let the home folks know, and stimulate further emigration. Settlements were largely along major rivers and inland. Single men were more likely to gravitate to cities or the western frontier.
The 1820 federal census provides a snapshot of Missourians at statehood. No copies of the original territorial census survive, but statistics were in contemporary newspapers. The population of the state, excluding indigenous people, was 66,607. Howard County, including a large area along the Missouri and Grand Rivers, led at 13,427, followed by St. Louis at 9732, and Cooper at 6959. Cape Girardeau County led in southeastern Missouri with 5965 people, followed by Ste. Genevieve (including Perry) at 5048, Washington at 3000, New Madrid at 2296, Madison at 2047, and Wayne at 1443. The population was 45.6% free white males, 37.8% free white females, 16.1% slaves, 0.4% free persons of color, and 0.1% persons bound to service.
