It has been generally accepted that the first inhabitants of North America migrated from Siberia by way of the Bering land bridge and arrived at least 12,000 years ago; however, some evidence suggests an even earlier date of arrival.[36][38] The Clovis culture, which appeared around 11,000 BC, is believed to represent the first wave of human settlement of the Americas. This was likely the first of three major waves of migration into North America; later waves brought the ancestors of present-day Athabaskans, Aleuts, and Eskimos.
Over time, indigenous cultures in North America grew increasingly complex, and some, such as the pre-Columbian Mississippian culture in the southeast, developed advanced agriculture, architecture, and complex societies. The city-state of Cahokia is the largest, most complex pre-Columbian archaeological site in the modern-day United States. In the Four Corners region, Ancestral Puebloan culture developed from centuries of agricultural experimentation. The Haudenosaunee, located in the southern Great Lakes region, was established at some point between the twelfth and fifteenth centuries.[45] Most prominent along the Atlantic coast were the Algonquian tribes, who practiced hunting and trapping, along with limited cultivation.[clarification needed]