The Peoria (or Peouaroua) are a Native American people, and historically, they were part of which organization, sometimes referred to as the Illiniwek or Illini, was a group of 12–13 Native American tribes in the upper Mississippi River valley of North America?
Peoria people:  Historically, they were part of the Illinois Confederation. Illinois Confederation: The Illinois Confederation, sometimes referred to as the Illiniwek or Illini, was a group of 12–13 Native American tribes in the upper Mississippi River valley of North America.
Illinois Confederation