Native Americans (US)+standards in field
Ethno-linguistic classification
Cultural regions of North American people at the time of European contact
Far from forming a single ethnic group, Native Americans were divided into several hundred ethno-linguistic groups, most of them grouped into the Na-Dené (Athabaskan), Algic (including Algonquian), Uto-Aztecan, Iroquoian, Siouan-Catawban, Yok-Utian, Salishan and Yuman-Cochimí phyla, besides many smaller groups and several language isolates. Demonstrating genetic relationships has proved difficult due to the great linguistic diversity present in North America.
The indigenous peoples of North America can be classified as belonging to a number of large cultural areas:
- Alaska Natives
- Arctic: Eskimo-Aleut
- Subarctic: Northern Athabaskan
- Western United States
- Central United States
- Eastern United States
Of the surviving languages, Uto-Aztecan has the most speakers (1.95 million) if the languages in Mexico are considered (mostly due to 1.5 million speakers of Nahuatl); Nadene comes in second with approximately 180,200 speakers (148,500 of these are speakers of Navajo). Na-Dené and Algic have the widest geographic distributions: Algic currently spans from northeastern Canada across much of the continent down to northeastern Mexico (due to later migrations of the Kickapoo) with two outliers in California (Yurok and Wiyot); Na-Dené spans from Alaska and western Canada through Washington, Oregon, and California to the U.S. Southwest and northern Mexico (with one outlier in the Plains). Another area of considerable diversity appears to have been the Southeast; however, many of these languages became extinct from European contact and as a result they are, for the most part, absent from the historical record.
http://en.wikipedia.org/wiki/Native_Americans_in_the_United_States#Ethno-linguistic_classification 06/09

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