Facsimile of Pierre Delliette's "Memoir concerning the Illinois Country."

Much of what we know about Illinois culture is based on two detailed French accounts written by men who visited or lived among the Illinois in the late 1600s. Jacques Marquette, a Jesuit priest, visited Peoria and Kaskaskia villages in 1673 and 1675. Marquette's journals and memoirs have been published in The Jesuit Relations and Allied Documents, Volume 59, edited by Reuben Gold Thwaites.

Another good source is a memoir written by a fur trader and military officer named Pierre Delliette. Delliette lived among the Peoria and Kaskaskia for eleven years, including four years at Fort St. Louis on Starved Rock (1687-1691) and seven years at Peoria (1691-1698). He wrote his memoir in about 1702 when he lived in a Wea Indian village located at Chicago. Delliette's memoir has been published twice. It first appeared, in the original French and with English translation, in the Collections of the Illinois State Historical Library, Volume 23, edited by Theodore Calvin Pease and Raymond C. Werner. The English translation was republished in a book edited by Milo Milton Quaife.

Most written descriptions of the Illinois pertain to the Peoria and Kaskaskia tribes; relatively little is known about the Cahokia, Michigamea, and Tamaroa tribes.