The Illinois Confederation was a political alliance formed by several Native American tribes in the early 18th century, primarily in the region that is now the state of Illinois. This confederation included tribes such as the Cahokia, Kaskaskia, and Peoria, who united to strengthen their position against European settlers and other Native American groups. The confederation aimed to maintain their sovereignty and control over their lands, as well as to facilitate trade and mutual defense. However, as European colonization expanded, the confederation faced significant challenges, leading to its eventual decline by the late 18th century.