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 people in Nebraska as present-day Illinois. Trappers and traders established relationships with Native American tribes at major points around the Great Lakes and along the Mississippi and Missouri rivers. In the Treaty of Fontainebleau in 1762, France ceded its lands west of the Mississippi River to Spain. In 1794 a French trapper named Jean-Baptiste Truteau established a trading post 30 miles up the Niobrara River. The next year, in 1795, Jacques D'Eglise traveled the Missouri River Valley on behalf of the Spanish crown. Searching for the elusive Northwest Passage, D'Eglise did not go any further than central North Dakota. In 1803 the United