History of St. Louis (1763–1803) History of St. Louis (1763–1803) The history of St. Louis, Missouri from 1763 to 1803 was marked by the transfer of French Louisiana to Spanish control, the founding of the city of St. Louis, its slow growth and role in the American Revolution under the rule of the Spanish, the transfer of the area to American control in the Louisiana Purchase, and its steady growth and prominence since then. In mid-1763, French Governor Jean-Jacques Blaise d'Abbadie granted a trade monopoly over the west upper Mississippi region to Gilbert Antoine de St. Maxent, a New Orleans merchant. Maxent quickly engaged the
French colonization of Texas Fontainebleau, following its defeat by Great Britain in the Seven Years' War. It ceded New France to Britain. In 1803, three years after Spain had returned Louisiana to France, Napoleon sold the territory to the United States. The original agreement between Spain and France had not explicitly specified the borders of Louisiana, and the descriptions in the documents were ambiguous and contradictory. The United States insisted that its purchase included all of the territory France had claimed, including all of Texas. The dispute was not resolved until the Adams-Onís Treaty of 1819, in which Spain ceded Florida to the United