Peoria are federally recognized as the Peoria Tribe of Indians of Oklahoma. Historically, they were one of the principal tribes of the Illinois confederacy. Early references to the Illinois which place them on the Mississippi, although some of the tribes were on Rock and Illinois rivers, must relate to the Peoria and locate them near the mouth of the Wisconsin. When Marquette and Joliet descended the Mississippi in 1673, they found them and the Moingwena on the west side of the Mississippi near the mouth of a river supposed to be the Des Moines, though it may have been one farther north. When Marquette returned from the south, he found that the Peo ria had removed and were near the lower end of the expansion of Illinois river, near the present Peoria. At the close of the war carried on by the Sauk and Foxes and other northern tribes against the Illinois, about 1768, the Kickapoo took possession of this village and made it their principal settlement.
About the same time a large part of the Peoria crossed over into Missouri, where they remained, building their village on Blackwater fork, until they removed to Kansas. One band, the Utagami, living near Illinois river, was practically exterminated, probably by the northern tribes, during the Revolutionary war (Gatschet, Sauk and Fox MS., B. A. E., 1882). Utagami, according to Dr Wm. Jones, may mean the Foxes who were known to the northern Algonquians as Utugamig, 'people of the other shore.' The Foxes claim to have annihilated the Peoria for the help they gave the French and other tribes in the wars against them (the Foxes). The main body of the Peoria remained on the east bank of Illinois river until 1832, when, together with the other tribes of the old Illinois confederacy, they sold to the United States their claims in Illinois and Missouri, and to the consolidated tribes, under the names of Peoria and Kaskaskia, was assigned a reservation on Osage river, Kansas. In 1854 the Wea and Piankashaw united with them, and in 1868 the entire body removed to Indian Territory (Oklahoma), where they now reside.
The early estimates of the numbers of the Peoria are altogether unreliable, and later estimates shed no light on their population from the fact that several Illinois tribes were then consolidated under the same name. In 1736 Chauvignerie estimated the Peoria at about 250 souls. They were so nearly exterminated soon afterward by the northern tribes that about the year 1800 Gov. William Henry Harrison of the Northwest Territory could find only 4 men of the tribe living. In 1829 the Indians consolidated under that name numbered 120. According to the report of the Indian Office the Peoria and allied tribes in Oklahoma numbered 192 in 1906.