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
St. Louis was founded in 1764 by French fur traders Pierre Laclède and Auguste Chouteau, and named after Louis IX of France. In 1764, following France's defeat in the Seven Years' War, the area was ceded to Spain and retroceded back to France in 1800. In 1803, the United States acquired the territory as part of the Louisiana Purchase. During the 19th century, St. Louis developed as a major port on the Mississippi River. In the 1870 Census, St. Louis was ranked as the 4th-largest city in the United States. It separated from St. Louis County in 1877, becoming an independent city