That year he became a missionary to the
Ponca Indians in the
Dakota Territory. His aptitude for languages and sympathetic personality won him the confidence of the Indians. He lived 27 months as a missionary in
Nebraska and
South Dakota, learning the difficult (for English speakers)
Siouan language of the Ponca and
Omaha Indians. Ill health forced Dorsey to leave the West and to become a pastor in Maryland. In 1878, in the formative period of the
Bureau of American Ethnology (BAE) as part of the
Smithsonian Institution, the director
John Wesley Powell engaged Dorsey to return to Nebraska to compile dictionaries of the Omaha and Ponca languages. In 1880, Dorsey returned to Washington to work with the BAE at the Smithsonian as a specialist in Siouan languages, a position he held for the rest of his life. Dorsey later did field work with the Siouan-speaking
Tutelo in
Canada, the
Biloxi in
Louisiana, and the
Quapaw in
Oklahoma. In addition, he studied several tribes along the
Oregon coast, where he compiled materials on the
Athabaskan (also called Dene),
Coosan,
Takilman, and
Yakonan language families or "stocks", some of which were spoken by small groups of people. and
Osage languages. He became the foremost expert on the languages and culture of southern Siouan peoples. Many of his extensive compilations of vocabulary, grammar, myths, oral histories, and cultural practices are still unpublished, but some of his papers are stored at the
National Anthropological Archives. and are undergoing digitization. Dorsey died of
typhoid fever in 1895 in
Washington, D.C. at age 47. ==See also==