Cahokia people

The Cahokia were a Native American tribe. They were apart of the Illinois Confederation, which was a group of tribes that lived in the Mississippi River Valley. They lived in what is now the Midwest of the United States in North America. They spoke an Algonquian language. The Cahokia were probably similar to other tribes in the Illinois Confederation.
Europeans named a group of man-made earthen mounds after the Cahokia, who lived nearby. However, scholars do not believe that the Cahokia tribe built the mounds.
French missionaries came to proselytize the Cahokia. They made the Tamaroa/Cahokia mission in 1699 CE and the River L'Abbė mission in 1735 CE. The Cahokia's population began to decline in the 18th century. This was probably because of war with other tribes, new infectious diseases, and cultural changes that disrupted their society.
Five Cahokia chiefs and headmen joined the other Illinois tribes at the 1818 Treaty of Edwardsville (Illinois). With this treaty, they ceded half of the state of Illinois to the United States government. The remaining Cahokia became apart of the Kaskaskia and Peoria people. The descendants of the Cahokia are now in Ottawa County, Oklahoma.