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
France–Spain relations Western Flanders, roughly equivalent to the modern French department of Nord, was also ceded. An anomaly of the treaty was that although all villages in Roussillon were ceded to France, Llívia was deemed to be a city and was therefore retained by Spain to the present day as an exclave into France. The treaty was signed on Pheasant Island, an uninhabited, unserviced island in the Bidasoa river between the French commune of Hendaye and the Spanish municipality of Irun. Both settlements, and therefore their countries, took sovereignty of the island for six months out of each year. After Philip IV