Spanish Louisiana in the context of "Ste. Genevieve National Historical Park"

Louisiana was a dominant population center in the southwest of the Confederate States of America, controlling the wealthy trade center of New Orleans, and contributing the French Creole and Cajun populations to the demographic composition of a predominantly Anglo-American country. In the antebellum period, Louisiana was a slave state, where enslaved African Americans had comprised the majority of the population during the eighteenth-century French and Spanish dominations. By the time the United States acquired the territory (1803) and Louisiana became a state (1812), the institution of slavery was entrenched. By 1860, 47% of the state's population were enslaved, though the state also had one of the largest free black populations in the United States. Much of the white population, particularly in the cities, supported slavery, while pockets of support for the U.S. and its government existed in the more rural areas.

Louisiana declared that it had seceded from the Union on January 26, 1861. Civil-War era New Orleans, the largest city in the South, was strategically important as a port city due to its southernmost location on the Mississippi River and its access to the Gulf of Mexico. The U.S. War Department early on planned for its capture. The city was taken by U.S. Army forces on April 25, 1862. Because a large part of the population had Union sympathies (or compatible commercial interests), the U.S. government took the unusual step of designating the areas of Louisiana then under U.S. control as a state within the Union, with its own elected representatives to the U.S. Congress. For the latter part of the war, both the U.S. and the Confederacy recognized their own distinct Louisiana governors. Similarly, New Orleans and 13 named parishes of the state were exempted from the Emancipation Proclamation, which applied exclusively to states in rebellion against the Union.

Saint Charles (commonly abbreviated St. Charles) is a city in and the county seat of St. Charles County, Missouri, United States. The population was 70,493 at the 2020 census, making St. Charles the eighth-most populous city in Missouri. Situated on the Missouri River near its mouth at the Mississippi, St. Charles is a northwestern suburb of St. Louis.

The city was founded circa 1769 as Les Petites Côtes, or "The Little Hills" in French, by Louis Blanchette, a French-Canadian fur trader. The St. Charles area was settled primarily by French-speaking colonists from Canada in its early days. This former French territory west of the Mississippi River was nominally ruled by Spain following France's defeat in the Seven Years' War, while France had also ceded the east of the Mississippi to Great Britain. St. Charles is thus the third-oldest city in what is now the state of Missouri. In the 18th and 19th century, the city's waterfront played a significant role as a river port for westward trade and expansion, including trade with Native American tribes on the upper Missouri River. In 1804 the Lewis and Clark Expedition considered this settlement the last "civilized" stop before they headed upriver to explore the western territory that the United States acquired from France in the Louisiana Purchase.