French Louisiana in 1754.
Louisiana was part of the French colony of New France, occupying the Mississippi Basin and the coast of the Gulf of Mexico between New Spain and Spanish Florida. The area was explored by the French in the late seventeenth century, when several settlements were established, notably New Orleans near the mouth of the Mississippi River, which became the capital of Louisiana in 1723.
Under the 1763 Treaty of Paris ending the French and Indian War, the French ceded Louisiana east of the Mississippi to Great Britain, while the area west of the river was ceded to France's ally Spain as compensation for the loss of Spanish Florida to the British. Many French settlers east of the Mississippi chose to relocate west of the river, preferring to live under the government of Catholic Spain rather than that of Protestant Britain. The city of St. Louis was founded by these settlers in 1764.
Under the Quebec Act of 1774, the area between the Mississippi and Ohio Rivers, known as the Illinois Country, was transferred to Quebec. Following the North American Rebellion of 1775 - 1778, British North America was reorganized by the Britannic Design of 1781 into the Confederation of North America. Under the Design, the Illinois Country was split from Quebec to form the Confederation of Indiana, with its capital at Fort Radisson.
During the Trans-Oceanic War of 1795 - 1799, Spanish Louisiana was conquered by the British, and incorporated into the C.N.A. as the Confederation of Vandalia.