St. Louis was founded soon after by French fur traders, Pierre Laclède and stepson Auguste Chouteau from New Orleans in 1764. From 1764 to 1803, European control of the area west of the Mississippi to the northernmost part of the Missouri River basin, called Louisiana, was assumed by the Spanish as part of the Viceroyalty of New Spain, due to Treaty of Fontainebleau (in order to have Spain join with France in the war against England). The arrival of the Spanish in St. Louis was in September 1767.