S., about half of which are associated with Indian reservations.The term excludes Native Hawaiians and some Alaska Natives.By comparison, the indigenous peoples of Canada are generally known as First Nations.

The ancestors of modern Native Americans arrived in what is now the United States at least 15,000 years ago, possibly much longer, from Asia through Beringia.

A vast variety of peoples, societies and cultures subsequently developed.

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.

While technically referring to the era before Christopher Columbus' voyages of 1492 to 1504, in practice the term usually includes the history of American indigenous cultures until they were conquered or significantly influenced by Europeans, even if this happened decades or even centuries after Columbus' initial landing.

Native American cultures are not normally included in characterizations of advanced stone age cultures as "Neolithic," which is a category that more often includes only the cultures in Eurasia, Africa, and other regions.

At the time of the first contact, the indigenous cultures were quite different from those of the proto-industrial and mostly Christian immigrants.

Some Northeastern and Southwestern cultures, in particular, were matrilineal and operated on a more collective basis than the Europeans were familiar with.

Expansion of European-American populations to the west after the American Revolution resulted in increasing pressure on Native American lands, warfare between the groups, and rising tensions. This resulted in the ethnic cleansing of many tribes, with the brutal, forced marches coming to be known as The Trail of Tears.

As American expansion reached into the West, settler and miner migrants came into increasing conflict with the Great Basin, Great Plains, and other Western tribes. Contemporary Native Americans have a unique relationship with the United States because they may be members of nations, tribes, or bands with sovereignty and treaty rights.

The archaeological periods used are the classifications of archaeological periods and cultures established in Gordon Willey and Philip Phillips' 1958 book Method and Theory in American Archaeology.