Boonslick

St. Louis was also a major settlement town since the 17th and 18th century era along with the nearby, across the river upstream to the east, of French colonial settlements Kaskaskia and Cahokia in the adjacent Illinois Country of the New France colonial empire of the old Kingdom of France, leading from its capital in Quebec (in future Canada) in the north, and east of the Great Lakes and extending southward through the central Mississippi River Valley down to the lower river port of New Orleans on the Gulf of Mexico and in French Louisiana, the heartland and central watershed of the North American continent.

St. Louis was also important because of its proximity to the confluence of the central Mississippi with the Ohio River flowing from the northeast and the Missouri River streaming from the far western Rocky Mountains northwest in the earlier federal Louisiana Territory (1804-1812), organized after the sale of the huge uncharted Louisiana Purchase of 1803, from the Emperor Napoleon I / Napoleon Bonaparte of France (the First French Empire) for $15 million dollars The western terminus of the Boone's Lick Road further west in Franklin also marked the eastern end and beginning of the continuing famous Santa Fe Trail, leading further southwestward across the Great Plains to Santa Fe, the Royal Spanish colonial capital of its province of New Mexico in the larger Viceroyalty of New Spain dominions of its Spanish Empire in the twin continents of the Americas (Western Hemisphere).

This well-known historical trail, first explored in 1806-1807, by U.S. Army officer Zebulon Pike (1779-1813), and his military expedition, eventually became a major conduit for continuing overland American-Spanish trade in the future Southwestern United States.

Its early French and Spanish colonial vestiges in old Louisiana were overtaken by settlement of newer European-American migrants moving westward from the Original Thirteen States on the East Coast, down the Ohio River from the Ohio Country, Pittsburgh and the Upland South — largely new states of Kentucky and Tennessee with its connecting tributary rivers from the south of the Tennessee and Cumberland streams, and crossing in the gaps / passes of the Appalachian Mountains chain, from Virginia further east — who brought numerous African-American slaves with them.

[3][4] The region's borders often vary in definition but have included the present-day counties of Boone, Callaway, Cooper, Howard, and Saline.