The present city of Council Bluffs was first settled by Sauganash's band of Potawatomi in 1838 after they were removed from what became Chicago. Sauganash's English name was Billy Caldwell, so the Potawatomis' main settlement was called Caldwell's Camp. The U.S. Dragoon built a small fort nearby where in 1838-1839, the missionary Pierre-Jean De Smet helped establish St. Joesph's Mission to minister to the Potawatomi. De Smet was appalled by the murder and brutality caused by the whiskey trade; he had little success in religious conversions, resorting to secret baptisms of Indian children. During this time he assisted and supported Joseph Nicollet’s efforts at mapping the Upper Midwest. De Smet used newly-acquired mapping skills to produce the first detailed map of the Missouri River valley