Through the decades changing conditions have led many business and political leaders to propose merging the city and county as a single government.

French colonists moved from east of the Mississippi River after France ceded territory to Great Britain after losing the Seven Years' War.

St. Louis was founded by Pierre Laclède and Auguste Chouteau on February 14, 1764; they became major fur traders in the city.

In 1823, Auguste Chouteau and John Baptiste Charles Lucas donated two tracts of land that formed a vacant square bounded by Broadway, Fourth, Chestnut, and Market.

[15] Between the summer of 1826 and 1833, a low-roofed two-story brick structure was built fronting Fourth Street; this was the first permanent courthouse for St. Louis County.

[6][16] Much of the dispute involved the double taxation of city residents and their proportionally lesser representation in county government.

[17] The reform of 1859, in which the County Court was abolished by the state government and replaced by a Board of Commissioners, was in large part a reaction to city outcry over mismanagement of tax money.

[17] Several plans began to circulate during the late 1860s that would relieve this burden, including home rule status for St. Louis, further reorganization of the County Court to ensure greater representation, city-county government consolidation, and separation of the two entities.

[18] A consolidation plan proceeded in the General Assembly in 1871, backed by city political leaders Anthony Ittner and Roderick E.

[18] The separation plan gained greater support when it became clear that the mistrust between city and county residents precluded consolidation.

[18] At the convention, a committee examined the issues of the St. Louis government, and it summarized the two options facing the region as consolidation and separation.

[20] On January 29, 1877, the Court considered a report that recommended Kirkwood as the new county seat, but did not decide the issue at that time.

[21] The Court continued to meet at the Sutton House in Maplewood until February 1877, when it convened at the Des Peres Grange Hall.

[22] In September 1877 the Court accepted the donation of 100 acres of land on Hanley Road by a farmer named Ralph Clayton.

[22] In addition to the benefit of donated land, the site was chosen because it was on the route of the Hodiamont streetcar line, which connected from St. Louis to Florissant.

[25] Webster Groves incorporated in 1896, prompted by residents' demands for a police department after the murder of Bertram Atwater, a commercial artist from Chicago.

After the Civil War, dozens of school districts opened in St. Louis County to provide basic primary education.

The western boundary with Franklin County is the north–south line where the distance between the Meramec and Missouri rivers is the shortest, bisecting the city of Pacific, roughly two blocks east of Hwy OO/F (First street).

It was formerly called "Gumbo Flats" after its rich, dark soil; it was submerged by at least ten feet of water during the Great Flood of 1993.

The Columbia Bottom is a floodplain in the northeast of the county at the confluence of the Mississippi and Missouri rivers; this is preserved as a conservation area open to the public.

The River des Peres drains the interior of the county before flowing into constructed underground channels into the City of St. Louis.

[34] The bedrock is mainly limestone and dolomite, and much of the county near the rivers is karst terrain, with numerous caves, sinkholes, and springs.

Since that time, large parks and undeveloped areas in the western and southern parts of the county have grown dense forest cover.

St. Louis County has the most recorded native species of plants in the state, but this is probably due to the intensive botanical research done in the area.

Eastern gray squirrel, cottontail rabbit, and other rodents are abundant, as well as opossum, beaver, muskrat, raccoon, and skunk.

Populations of honeybees have sharply declined in recent years, and numerous species of pollinator insects have filled their ecological niche.

Fall is mild, with lower humidity and can produce intermittent bouts of heavy rainfall with the first snow flurries usually forming in late November.

Winter storm systems, such as Alberta clippers, can bring days of heavy freezing rain, ice pellets, and snowfall.

The racial makeup of the county in 2010 was 68.3% White (66.9% Non-Hispanic White), 25.3% African American, 0.2% Native American, 3.5% Asian (1.1% Asian Indian, 1.0% Chinese, 0.3% Filipino, 0.3% Korean, 0.3% Vietnamese, 0.1% Japanese, 0.4% Other), 0.03% Pacific Islander, 0.9% from other races, and 1.9% from two or more races and 2.5% Hispanic or Latino (1.5% Mexican, 0.2% Puerto Rican, 0.1% Cuban, 0.8% Other).

As of 2009, the largest employment sectors in St. Louis County are education and health (25.2%), trade and transportation (19.6%), and professional business services (12.7%).