member of any of the aboriginal peoples of the Western Hemisphere. Eskimos (Eskimo) (Inuit and Yupik/Yupiit) and Aleuts (Aleut) are often excluded from this category because their closest genetic and cultural relations were and are with other Arctic peoples (Arctic) rather than the groups to their south. (See also Sidebar: Tribal Nomenclature: American Indian, Native American, and First Nation.)

Discussions of indigenous cultures are often organized geographically. The Western Hemisphere typically comprises three regions: Northern America (present-day United States and Canada), Middle America (present-day Mexico and Central America), and South America.

The earliest ancestors of Native Americans (Native American) are known as Paleo-Indians. They shared certain cultural traits with their Asian contemporaries, such as the use of fire and domesticated dogs; they do not seem to have used other Old World technologies such as grazing animals, domesticated plants, and the wheel.

Beginning some 11,500 years ago, the climate in the Northern Hemisphere slowly became warmer and drier. Temperatures rose significantly over the next several thousand years, eventually averaging a few degrees higher than those experienced in the same areas during the early 21st century. Cold-adapted plant species such as birch and spruce retreated to the mountains and the far north, replaced in lower altitudes and latitudes by heat- and drought-resistant species including grasses, forbs, and hardwood trees. Very large animals such as mammoths and giant ground sloths were unable to cope with the change and became extinct; other species, such as bison, survived by becoming smaller.

Archaic technology included grinding tools (mortars and pestles), woodworking tools (grooved stone axes and gouges), and items such as plummets whose use is not clear. Archaic hunting tools are distinguished by the introduction of the spear-thrower, which enables a hunter to throw a dart accurately and with great force at a distant target; so-called bird stones (bird stone) may have augmented the hunter's throwing power. Large fluted points became less popular, replaced by smaller side-notched points more appropriate for dart-based hunting.

In adopting a broad array of social, economic, and technological innovations, Archaic peoples enjoyed a long period of relative stability. Although the duration of the Archaic Period varied greatly depending upon location, it persisted from as early as 8000 BC until at least 2000 BC in most of Northern America. In areas that were either unusually prosperous or, conversely, unsuitable for agriculture—the rich microclimates of California and the salmon-rich Plateau and Pacific Northwest in the former case and the cool interior of northern Canada in the latter—foraging societies persisted well into the 19th century AD. (See also agriculture, origins of.)

Early Southwest Indians (Southwest Indian) began to grow corn and squash by approximately 1200 BC, but they could not produce reliable harvests until they had resolved problems arising from the region's relative aridity. Mogollon (Mogollon culture) innovations in the use of small dams to pool rainfall and divert streams for watering crops made agriculture possible, and these innovations were adopted and further developed by the Ancestral Pueblo (Ancestral Pueblo culture) (Anasazi (Ancestral Pueblo culture)) peoples; the neighbouring Hohokam (Hohokam culture) also depended on irrigation. In addition to corn and squash, the peoples of this region cultivated several varieties of beans, peppers, and long-staple cotton.

Southwestern cultures came to be characterized by complex pueblo architecture: great cliff houses with 20 to 1,000 rooms and up to four stories. A period of increasing aridity beginning in approximately AD 1100 put great stress on these societies, and they abandoned many of their largest settlements by the end of the 14th century. (See also Native American: Prehistory (Native American).)

Spain, France, England (British Empire), and Russia colonized Northern America for reasons that differed from one another's and that were reflected in their formal policies concerning indigenous peoples. The Spanish colonized the Southeast, the Southwest, and California. Their goal was to create a local peasant class; indigenous peoples were missionized, relocated, and forced to work for the Spanish crown and church, all under threat of force. The French occupied an area that reached from the present state of Louisiana to Canada and from the Atlantic coast to the Mississippi River, and they claimed territory as far west as the Rocky Mountains. They were primarily interested in extracting saleable goods, and French traders and trappers frequently smoothed the exchange process (and increased their personal safety and comfort) by marrying indigenous women and becoming adoptive tribal members. The English, by contrast, sought territorial expansion; focusing their initial occupation on the mid- and north-Atlantic coasts and Hudson Bay, they prohibited marriage between British subjects and indigenous peoples. The Russians sought to supply Chinese markets with rich marine mammal furs from the Northwest Coast and the Arctic; unfamiliar with oceangoing prey, they forced indigenous men to hunt sea otters. These European powers fought territorial wars in Northern America from the 16th through the 18th century and frequently drew indigenous peoples into the conflicts. (See Native American: History (Native American).)

Assimilationist strategies were also implemented on reservations. It was not unusual for governmental authorities to prohibit indigenous religious practices such as the potlatch and Sun Dance in the hope that cultural continuity would be broken and Christianity adopted. Many of the hunting, fishing, and gathering rights guaranteed in treaties—which had remained essential to the indigenous economy—were abrogated by a combination of hunting regulations, mobility or “pass” laws, and the depletion of wild resources. In combination these factors demoralized and impoverished many native peoples and created a de facto system of apartheid in Northern America.

The earliest well-attested archaeological site in the Americas is Monte Verde, Chile (c. 10,500 BC); Paleo-Indians must have journeyed through (or along the coast of) Middle America sometime earlier in order to reach Monte Verde by that date. Estimates of the timing of this passage vary widely, ranging from perhaps 11,000 BC to more than 20,000 BC.

Not all prehistoric peoples in Middle America lived in cities; most lived in relatively small rural settlements. Spanish colonizers described villages in which the basic social units were nuclear and extended families, dominated by male members and elders; barter-based market economies and complex religious traditions were also characteristic of these groups. While it is difficult to know the extent to which the Spanish accounts reflect reality from the Indians' perspective, cultural patterns like these have been common in the region since the 16th century. (See also Middle American Indian: The prehistoric period (Middle American Indian); pre-Columbian civilizations: Mesoamerican civilization (pre-Columbian civilizations).)

As the primary European power in Middle America, Spain focused on the extraction of wealth, the increase of territory, and the production of a Catholicized peasant class. During the first period of colonization, Spanish Jesuits set up missions and reservations in northwestern Middle America; these usually included housing for clergy, indigenous peoples, and (in some cases) soldiers, as well as a church, outbuildings, and agricultural land. Other sectors were settled via encomiendas (encomienda), essentially feudal estates granted to conquistadors and others who had provided service to the Spanish crown. Through these estates, plantation farming, cattle ranching, and mining became the economic engines of colonial society. Although Spanish missionization was carried out with fervour, indigenous Middle American religious practices did not disappear; instead, they became notably syncretic, mixing remnants of earlier ritual practices— animism, shamanism, and divination—with the veneration of individual Christian saints, such as Our Lady of Guadalupe (Guadalupe, Our Lady of).

Paleo-Indians reached South America by at least 12,500 years ago, and perhaps much earlier. They settled in what are now Tierra del Fuego, Argentina, southern Chile, the south-central plains of the Gran Chaco region, and portions of the central Andes. As with other very early indigenous Americans, this region's earliest peoples organized themselves into small kin-based groups to facilitate their movement to areas of more plentiful game or more favourable climatic conditions.

Early farming societies developed on the coasts of Brazil and Arawak, in the Greater Antilles, and in some parts of the inland forests and highlands. Domesticates from South America include squash (c. 8400–8000 BC), peanuts (c. 6500 BC), lima beans (c. 5000 BC), potatoes (c. 2500 BC), and cavies (guinea pigs; c. 1000 BC); domesticated corn and cassava began to be used in South America between about 2000 and 1500 BC. South American groups engaged in shifting agriculture as early as 3000 BC; also called slash-and-burn agriculture or swiddening, this technique involved the periodic relocation of the entire community to a place some miles away due to the exhaustion of local fields or garden plots.

Parts of South America supported permanent settlements; especially in the highlands, many of these communities raised cotton, tomatoes, llamas, and alpacas. The peoples of the Caribbean and the northern Andes developed complex societies based on military and ritual leadership. Warfare was important among these nations as a vehicle for social advancement within the tribe and as a means of supplying slaves and victims for ritual sacrifices. Preliminary forms of centralized rule also distinguished these societies from the relatively egalitarian communities of the forests.

The Spanish, Portuguese, and Dutch conquests of the 16th century affected indigenous South Americans in a variety of ways that ranged from near extinction (generally through a combination of disease and violence) to absorption into colonial society. The most severely affected native cultures were those dwelling along major navigational routes and those of the Inca empire. The former suffered from nearly continuous exposure to the violence of conquest, while the Inca empire was systematically taken over by the colonizers. While the Inca aristocratic and artisan classes were to some extent absorbed into the colonial hierarchy, the native farming population was relegated to menial servitude. In the less-exploited rural Andean regions, descendants of the Inca nation have preserved some of their cultural heritage.

In the 18th and 19th centuries some South American Indian groups such as the Araucanians (Araucanian) successfully resisted Spanish domination. Although most were eventually assimilated or assigned to reservations, many retained their traditional languages and cultures well into the 20th century. By the early 21st century, many indigenous South American peoples were exercising increasing political and economic power, particularly in relation to commerce, tourism, and the tensions between development schemes and the preservation of regional ecosystems. The first Native American head of state, Juan Evo Morales Aymo (Morales, Evo), became president of Bolivia in 2006. (See also South American Indian: Evolution of contemporary cultures (South American Indian).)