The U.S. Census Bureau defines American Indians and Alaska Natives as people whose ancestry derives from any of the original peoples of North and South America, and who maintain tribal affiliation or community attachment. The Census presently counts as an Indian anyone who declares himself or herself to be an Indian. Native Hawaiians and other Pacific Islanders are not considered "Indians” under U.S. law and are enumerated separately in the Census. See Chapter Aa on population characteristics and Chapter Ef on outlying areas for information on Hawaiians and other Pacific Islanders.

From the perspective of historical ethnography, an Indian tribe is a body of people bound together by a common ancestry and continuity in culture and social organization. Tribal members occupied a defined territory and spoke a common language or dialect. Many precontact tribes have disappeared or were absorbed into other tribes. Today, there are more than 550 federally recognized tribes in the United States, including 223 village groups in Alaska.

"Federally recognized” means these tribes and groups have a special, legal relationship with the U.S. government. That special relationship is based on four principles:

Relations with the tribes are codified in treaties ratified by Congress, judicial opinions, and by executive orders issued by the President and by the Secretary of the Interior. The U.S. Bureau of Indian Affairs (BIA) is the principal agent of the United States in carrying out the government-to-government relationship that exists. It also acts as the principal agent of the U.S. government in carrying out the responsibilities the United States has as a trustee for property it holds for federally recognized tribes and individual American Indians. A number of Indian groups do not have a federally recognized status, although some are recognized by the states in which they are located. This means they have no relations with the BIA or the programs it operates. A special program at the BIA, however, works with groups seeking federal status. Of the 150 petitions for federal recognition the BIA has received since 1978, twelve groups have received acknowledgment through the BIA process, two had their status clarified by the Department of the Interior through other means, and seven were restored or recognized by Congress.

In 1924 Congress granted American citizenship to all Indians born in the territorial limits of the United States. Before that date, however, citizenship had been conferred upon approximately two thirds of the Indian population through treaty agreements, statutes, naturalization proceedings, and by service in the armed forces during World War I. No single federal or tribal criterion establishes a person's identity as an Indian. Tribes have varying eligibility criteria for membership.

In the essay that follows, C. Matthew Snipp uses – for editorial convenience – the term "American Indian” consistently in lieu of the more cumbersome "American Indian and Alaska Native,” and in lieu of other equally appropriate nomenclature, such as "Native American.”