Paleo-Indians and Settlement of the Americas This map shows the approximate location of the ice-free corridor and specific Paleoindian sites Clovis theory. It is not definitively known how or when the Native Americans first settled the Americas and the present-day United States. The prevailing theory proposes that people migrated from Eurasia across Beringia , a land bridge that connected Siberia to present-day Alaska during the Ice Age , and then spread southward throughout the Americas over the subsequent generations. Genetic evidence suggests at least three waves of migrants arrived from Asia, with the first occurring at least 15 thousand years ago.
These groupings were generally based on peoples that shared the same culture, language, religion, customs, and politics. Sometimes tribes were also grouped by the region of the United States they lived in like the Great Plains Indians or by the type of language they spoke like the Apache. Below are some of the major groupings and tribes. They include the Inuit people of Alaska who lived primarily off of whale and seal meat. Californian - Tribes living in the area that is today the state of California such as the Mohave and the Miwok.