One of the largest settlements was located at the Cahokia site in the town of East St. Louis, Illinois. The settlement at Cahokia expanded so dramatically in 1050 that the lead archeologist writing about the site, Timothy R. Pauketat, refers to the changes of that year as the Big Bang. After the Big Bang, some 20,000 lived in the city or nearby suburbs, making Cahokia the largest urban complex in the continental U.S. before 1492 and half the size of contemporary Chichén Itzá.
