Peter John De Smet, an American missionary, born in Dendermonde, Belgium, Dec. 31, 1801, died in St. Louis, May 23, 1873. He arrived in Philadelphia in August, 1821, entered the Jesuit novitiate at Whitemarsh, Md., went to Missouri in 1823, and aided in founding the university of St. Louis, in which he labored till 1838, when he was sent to found a mission among the Pottawattarnies. His success caused him to be sent to the Flatheads in 1840, and to the Blackfeet soon afterward. He then planned a regular system of missionary establishments, which were taken charge of by his brother Jesuits, reserving to himself a general superintendence over them and the duty of providing funds for their support. He published several papers in the United States and in Europe for the purpose of creating public interest in favor of these missions, repeatedly visited Belgium and other Catholic countries to collect alms and obtain missionaries, and established several new missionary centres on both sides of the Rocky mountains. During a last voyage undertaken for the missions he sustained injuries which resulted in his death.

His principal works are: "Letters and Sketches, and Residence in the Rocky Mountains" (Philadelphia, 1843); "Oregon Missions, and Travels over the Rocky Mountains " (New York, 1847); "Western Missions and Missionaries" and "New Indian Sketches " (New York, 1863); and Reisen zu den Felsengebirgen und ein Jahr unter den wilder Indianerstdmmen des Oregon-Gebietes (St. Louis, 1865).