History

Native Americans and European settlers
See also: Native Americans in the United States, European colonization of the Americas, and Thirteen Colonies
The indigenous peoples of the U.S. mainland, including Alaska Natives, are most commonly believed to have migrated from Asia. They began arriving at least 12,000 and as many as 40,000 years ago.[27] Some, such as the pre-Columbian Mississippian culture, developed advanced agriculture, grand architecture, and state-level societies. After Europeans began settling the Americas, many millions of indigenous Americans died from epidemics of imported diseases such as smallpox.[28]