The language of the Dakota people was first put into written form by missionaries who lived within and learned from the Dakota community in the Minnesota River valley. John P. Williamson (1835-1917), son of missionary Dr. Thomas S. Williamson, grew up speaking both English and Dakota, then spent most of his adult life as a missionary on the Santee Reservation in northeastern Nebraska. In 1902, he produced An English-Dakota Dictionary.

A companion volume, A Dakota-English Dictionary by Stephen R. Riggs, is also available from the Minnesota Historical Society Press. These two dictionaries preserve the older language and remian the most comprehensive and accurate lexicons available. They are essential cultural and linguistic sources for all Students of the Dakota Language as well as historians, anthropologists, linguists, and ethnologists.