Spanish Expedition to Establish St. Louis

Background. During negotiations for the 1763 Treaty of Paris, French negotiators agreed to transfer France's colonial territories west of the Mississippi and Missouri rivers to New Spain, compensating Spain for territorial losses in the Seven Years' War. In 1764, after France lost that war, Pierre Laclède and his stepson Auguste Chouteau founded the settlement that became St. Louis, near the confluence of the Mississippi and Missouri rivers.

Ulloa's Governorship. Antonio de Ulloa y de la Torre-Guiral was a Spanish Navy officer who achieved the rank of vice admiral. Following the Seven Years' War, the Crown appointed him in 1765 as the first governor of Spanish Louisiana, and he reached New Orleans, the region's major city and port, on 5 March 1766. His rule was strongly resisted by the French Creoles of New Orleans, who expelled him from the city during the Rebellion of 1768.

St. Louis in the Early Spanish Period. The settlement founded by Laclède and Chouteau in 1764 developed within the former French lands now nominally under Spanish control. By 1765 the city began receiving visits from representatives of the British, French, and Spanish governments, and French families built its economy on the fur trade with the Osage and more distant tribes along the Missouri River.