Cahokia was a pre-Columbian Native American city located near present-day St. Louis, Missouri, and it was the largest and most influential urban settlement of the Mississippian culture, flourishing from approximately 1050 to 1350 AD. Known for its complex society, Cahokia featured large earthen mounds, sophisticated agricultural practices, and extensive trade networks, reflecting its role as a central hub of cultural and economic activity in North America during its peak.