Illinois Country in the context of "St. Louis"

Illinois (/ˌɪlɪˈnɔɪ/ IL-ih-NOY) is a state in the Midwestern region of the United States. It borders Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash and Ohio rivers to its south. Of the fifty U.S. states, Illinois has the fifth-largest gross domestic product (GDP), the sixth-largest population, and the 25th-most land area. Its capital city is Springfield in the center of the state, and the state's largest city is Chicago in the northeast.

Present-day Illinois was inhabited by Indigenous cultures for thousands of years. The French were the first Europeans to arrive, settling near the Mississippi and Illinois rivers in the 17th century Illinois Country, as part of their sprawling colony of New France. A century later, the revolutionary war Illinois campaign prefigured American involvement in the region. Following U.S. independence in 1783, which made the Mississippi River the national boundary, American settlers began arriving from Kentucky via the Ohio River. Illinois was soon part of the United States' oldest territory, the Northwest Territory, and in 1818 it achieved statehood. The Erie Canal brought increased commercial activity in the Great Lakes, and the invention of the self-scouring steel plow by Illinoisan John Deere turned the state's rich prairie into some of the world's most productive and valuable farmland, attracting immigrant farmers from Germany, Sweden and elsewhere. In the mid-19th century, the Illinois and Michigan Canal and a sprawling railroad network facilitated trade, commerce, and settlement, making the state a transportation hub for the nation, especially in the city of Chicago, which became the world's fastest growing city by the late 19th century. By 1900, the growth of industrial jobs in the northern cities and coal mining in the central and southern areas attracted immigrants from Eastern and Southern Europe. Illinois became one of America's most industrialized states and remains a major manufacturing center. The Great Migration from the South established a large Black community, particularly in Chicago, which became a leading cultural, economic, and population center; its metropolitan area, informally referred to as Chicagoland, holds about 65% of the state's 12.8 million residents.

Pierre Laclède Liguest or Pierre Laclède (22 November 1729 – 20 June 1778) was a French fur trader who, with his young assistant and stepson Auguste Chouteau, founded St. Louis in 1764, in what was then Spanish Upper Louisiana, in present-day Missouri.

Louisiana (Spanish: Luisiana, [la lwiˈsjana]) was a province of New Spain from 1762 to 1801. It was primarily located in the center of North America encompassing the western basin of the Mississippi River plus New Orleans. The area had originally been claimed and controlled by France, which had named it La Louisiane in honor of King Louis XIV in 1682. Spain secretly acquired the territory from France near the end of the Seven Years' War by the terms of the Treaty of Fontainebleau (1762). The actual transfer of authority was a slow process, and after Spain finally attempted to fully replace French authorities in New Orleans in 1767, French residents staged an uprising which the new Spanish colonial governor did not suppress until 1769. Spain also took possession of the trading post of St. Louis and all of Upper Louisiana in the late 1760s, though there was little Spanish presence in the wide expanses of what they called the "Illinois Country".

New Orleans was the main port of entry for Spanish supplies sent to American forces during the American Revolution, and Spain and the new United States disputed the borders of Louisiana and navigation rights on the Mississippi River for the duration of Spain's rule in the colony. New Orleans was devastated by large fires in 1788 and 1794 which destroyed most of the original wooden buildings in what is today the French Quarter. New construction was done in the Spanish style with stone walls and slate roofs, and new public buildings constructed during the city's Spanish period include several still standing today such as the St. Louis Cathedral, the Cabildo, and the Presbytere.

The Illinois River (Miami-Illinois: Inoka Siipiiwi) is a principal tributary of the Mississippi River at approximately 273 miles (439 km) in length. Located in the U.S. state of Illinois, the river has a drainage basin of 28,756.6 square miles (74,479 km). The Illinois River begins with the confluence of the Des Plaines and Kankakee rivers in the Chicago metropolitan area, and it generally flows to the southwest across Illinois, until it empties into the Mississippi near Grafton, Illinois. Its drainage basin extends into southeastern Wisconsin, northwestern Indiana, and a very small area of southwestern Michigan in addition to central Illinois. Along its banks are several river ports, including the largest, Peoria, Illinois. Historic and recreation areas on the river include Starved Rock, and the internationally important wetlands of the Emiquon Complex and Dixon Waterfowl Refuge.

The river was important among Native Americans and French traders as the principal water route connecting the Great Lakes with the Mississippi. The French colonial settlements along these rivers formed the heart of the area known as the Illinois Country in the 17th and 18th centuries. After the construction of the Illinois and Michigan Canal and the Hennepin Canal in the 19th century, the role of the river as link between Lake Michigan and the Mississippi was extended into the era of modern industrial shipping. The Illinois now forms the basis for the Illinois Waterway, extending the river's capabilities for navigation and commercial shipping.

Louisiana, also known as French Louisiana, was a district of New France. In 1682, the French explorer René-Robert Cavelier, Sieur de la Salle erected a cross near the mouth of the Mississippi River and claimed the whole of the drainage basin of the Mississippi River in the name of King Louis XIV, naming it "Louisiana". This land area stretched from near the Great Lakes to the Gulf of Mexico and from the Appalachian Mountains to the Rocky Mountains. The area was under French control from 1682 to 1762 and in part from 1801 (nominally) to 1803.

Louisiana included two regions, now known as Upper Louisiana (la Haute-Louisiane), which began north of the Arkansas River, and Lower Louisiana (la Basse-Louisiane). The U.S. state of Louisiana is named for the historical region, although it is only a small part of the vast lands claimed by France.

The Province of Quebec (French: Province de Québec) was a colony in British North America which comprised the former French colony of Canada. It was established by the Kingdom of Great Britain in 1763, following the conquest of New France by British forces during the Seven Years' War. As part of the 1763 Treaty of Paris, France gave up its claim to the colony; it instead negotiated to keep the small profitable island of Guadeloupe.

Following the Royal Proclamation of 1763, Canada was renamed the Province of Quebec, and from 1774 extended from the coast of Labrador on the Atlantic Ocean, southwest through the Saint Lawrence River Valley to the Great Lakes and beyond to the confluence of the Ohio and Mississippi Rivers in the Illinois Country. Portions of its southwest, those areas south of the Great Lakes, were later ceded to the newly established United States in the 1783 Treaty of Paris at the conclusion of the American Revolution; although the British maintained a military presence there until 1796 and the Jay Treaty. In 1791, the territory north of the Great Lakes was reorganised and divided into Lower Canada and Upper Canada.

St. Clair County is the ninth most populous county in Illinois. Located directly east of St. Louis, the county is part of the Metro East region of the Greater St. Louis metropolitan area in southern Illinois. As of the 2020 United States census, St. Clair County had a population of 257,400, making it the second most populous county in Illinois outside the Northern Third. Belleville is the county seat and largest city.

Along the Mississippi River, Cahokia Village was founded in 1697 by French settlers and served as a Jesuit mission to convert tribes of the Illinois Confederation to Christianity. The area became the center of the French Illinois Country. Prior to the establishment of Illinois as a state, the government of the Northwest Territory created St. Clair County in 1790. In 1809, the county became the administrative center of the Illinois Territory and one of the two original counties of Illinois, alongside Randolph County. In 1970, the United States Census Bureau placed the mean center of U.S. population, which generally has moved west every decennial census, in St. Clair County.