Population figures for the Indigenous peoples of the Americas prior to European colonization have been difficult to establish. By the end of the 20th century, most scholars gravitated toward an estimate of around 50 million, with some historians arguing for an estimate of 100 million or more.^[1][2]

In an effort to circumvent the hold which the Ottoman Empire held on the overland trade routes to East Asia and the hold that the Aeterni regis granted to Portugal on maritime routes via the African coast and the Indian Ocean, the monarchs of the nascent Spanish Empire decided to fund Columbus' voyage in 1492, which eventually led to the establishment of colonies and the migration of millions of Europeans to the Americas. The population of African and European peoples in the Americas grew steadily, starting in 1492, and at the same time, the Indigenous population began to plummet. Eurasian diseases such as influenza, pneumonic plagues, and smallpox, in combination with conflict, forced removal, enslavement, imprisonment, and outright warfare with European newcomers reduced populations and disrupted traditional societies.^[3][4] The causes of the decline and the extent of it have been characterized as a genocide by some scholars^[5][6][7] while other scholars have disputed this characterization.^[6][8][9]

Pre-Columbian population figures are difficult to estimate because of the fragmentary nature of the evidence. Estimates range from 8–112 million.^[10] Scholars have varied widely on the estimated size of the Indigenous populations prior to colonization and on the effects of European contact.^[11] Estimates are made by extrapolations from small bits of data. In 1976, geographer William Denevan used the existing estimates to derive a "consensus count" of about 54 million people. Nonetheless, more recent estimates still range widely.^[12] In 1992, Denevan suggested that the total population was approximately 53.9 million and the populations by region were, approximately, 3.8 million for the United States and Canada, 17.2 million for Mexico, 5.6 million for Central America, 3 million for the Caribbean, 15.7 million for the Andes and 8.6 million for lowland South America.^[13] A 2020 genetic study suggests that prior estimates for the pre-Columbian Caribbean population may have been at least tenfold too large.^[14] Historian David Stannard estimates that the extermination of Indigenous peoples took the lives of 100 million people: "...the total extermination of many American Indian peoples and the near-extermination of others, in numbers that eventually totaled close to 100,000,000."^[15] A 2019 study estimates the pre-Columbian Indigenous population contained more than 60 million people, but dropped to 6 million by 1600, based on a drop in atmospheric CO₂ during that period.^[16][17] Other studies have disputed this conclusion.^[18][19]

The Indigenous population of the Americas in 1492 was not necessarily at a high point and may actually have already been in decline in some areas. Indigenous populations in most areas of the Americas reached a low point by the early 20th century.^[20]

Using an estimate of approximately 37 million people in Mexico, Central and South America in 1492 (including 6 million in the Aztec Empire, 5–10 million in the Mayan States, 11 million in what is now Brazil, and 12 million in the Inca Empire), the lowest estimates give a death toll from all causes of 80% by the end of the 17th century (nine million people in 1650).^[21] Latin America would match its 15th-century population early in the 19th century; it numbered 17 million in 1800, 30 million in 1850, 61 million in 1900, 105 million in 1930, 218 million in 1960, 361 million in 1980, and 563 million in 2005.^[21] In the last three decades of the 16th century, the population of present-day Mexico dropped to about one million people.^[21] The Maya population is today estimated at six million, which is about the same as at the end of the 15th century, according to some estimates.^[21] In what is now Brazil, the Indigenous population declined from a pre-Columbian high of an estimated four million to some 300,000. Over 60 million Brazilians possess at least one Native South American ancestor, according to a DNA study.^[22]

While it is difficult to determine exactly how many Natives lived in North America before Columbus,^[23] estimates range from 3.8 million, as mentioned above, to 7 million^[24] people to a high of 18 million.^[25] Scholars vary on the estimated size of the Indigenous population in what is now Canada prior to colonization and on the effects of European contact.^[26] During the late 15th century is estimated to have been between 200,000^[27] and two million,^[28] with a figure of 500,000 currently accepted by Canada's Royal Commission on Aboriginal Health.^[29] Although not without conflict, European Canadians' early interactions with First Nations and Inuit populations were relatively peaceful.^[30] However repeated outbreaks of European infectious diseases such as influenza, measles and smallpox (to which they had no natural immunity),^[31] combined with other effects of European contact, resulted in a twenty-five percent to eighty percent Indigenous population decrease post-contact.^[27] Roland G Robertson suggests that during the late 1630s, smallpox killed over half of the Wyandot (Huron), who controlled most of the early North American fur trade in the area of New France.^[32] In 1871 there was an enumeration of the Indigenous population within the limits of Canada at the time, showing a total of only 102,358 individuals.^[33] From 2006 to 2016, the Indigenous population has grown by 42.5 percent, four times the national rate.^[34] According to the 2011 Canadian Census, Indigenous peoples (First Nations – 851,560, Inuit – 59,445 and Métis – 451,795) numbered at 1,400,685, or 4.3% of the country's total population.^[35]

The population debate has often had ideological underpinnings.^[36] Low estimates were sometimes reflective of European notions of cultural and racial superiority. Historian Francis Jennings argued, "Scholarly wisdom long held that Indians were so inferior in mind and works that they could not possibly have created or sustained large populations."^[37] In 1998, Africanist Historian David Henige said many population estimates are the result of arbitrary formulas applied from unreliable sources.^[38]

Genetic diversity and population structure in the American land mass using DNA micro-satellite markers (genotype) sampled from North, Central, and South America have been analyzed against similar data available from other Indigenous populations worldwide.^[85][86] The Amerindian populations show a lower genetic diversity than populations from other continental regions.^[86] Decreasing genetic diversity with increasing geographic distance from the Bering Strait can be seen, as well as a decreasing genetic similarity to Siberian populations from Alaska (genetic entry point).^[85][86] A higher level of diversity and lower level of population structure in western South America compared to eastern South America is observed.^[85][86] A relative lack of differentiation between Mesoamerican and Andean populations is a scenario that implies coastal routes were easier than inland routes for migrating peoples (Paleo-Indians) to traverse.^[85] The overall pattern that is emerging suggests that the Americas were recently colonized by a small number of individuals (effective size of about 70–250), and then they grew by a factor of 10 over 800–1,000 years.^[87][88] The data also show that there have been genetic exchanges between Asia, the Arctic and Greenland since the initial peopling of the Americas.^[88][89] A new study in early 2018 suggests that the effective population size of the original founding population of Native Americans was about 250 people.^[90][91]

Early explanations for the population decline of the Indigenous peoples of the Americas include the brutal practices of the Spanish conquistadores, as recorded by the Spaniards themselves, such as the encomienda system, which was ostensibly set up to protect people from warring tribes as well as to teach them the Spanish language and the Catholic religion, but in practice was tantamount to serfdom and slavery.^[92] The most notable account was that of the Dominican friar Bartolomé de las Casas, whose writings vividly depict Spanish atrocities committed in particular against the Taínos.^[93] The second European explanation was a perceived divine approval, in which God removed the natives as part of His "divine plan" to make way for a new Christian civilization. Many Native Americans viewed their troubles in a religious framework within their own belief systems.^[94]

According to later academics such as Noble David Cook, a community of scholars began "quietly accumulating piece by piece data on early epidemics in the Americas and their relation to the subjugation of native peoples." Scholars like Cook believe that widespread epidemic disease, to which the natives had no prior exposure or resistance, was the primary cause of the massive population decline of the Native Americans.^[95] One of the most devastating diseases was smallpox, but other deadly diseases included typhus, measles, influenza, bubonic plague, cholera, malaria, tuberculosis, mumps, yellow fever and pertussis, which were chronic in Eurasia.^[96]

However, recently scholars have studied the link between physical colonial violence such as warfare, displacement, and enslavement, and the proliferation of disease among Native populations.^[4][97][98] For example, according to Coquille scholar Dina Gilio-Whitaker, "In recent decades, however, researchers challenge the idea that disease is solely responsible for the rapid Indigenous population decline. The research identifies other aspects of European contact that had profoundly negative impacts on Native peoples' ability to survive foreign invasion: war, massacres, enslavement, overwork, deportation, the loss of will to live or reproduce, malnutrition and starvation from the breakdown of trade networks, and the loss of subsistence food production due to land loss."^[99]

Further, Andrés Reséndez of the University of California, Davis points out that, even though the Spanish were aware of deadly diseases such as smallpox, there is no mention of them in the New World until 1519, implying that, until that date, epidemic disease played no significant part in the depopulation of the Antilles. The practices of forced labor, brutal punishment, and inadequate necessities of life, were the initial and major reasons for depopulation.^[100] Jason Hickel estimates that a third of Arawak workers died every six months from forced labor in these mines.^[101] In this way, "slavery has emerged as a major killer" of the indigenous populations of the Caribbean between 1492 and 1550, as it set the conditions for diseases such as smallpox, influenza, and malaria to flourish.^[100] Unlike the populations of Europe who rebounded following the Black Death, no such rebound occurred for the Indigenous populations.^[100]

Similarly, historian Jeffrey Ostler at the University of Oregon has argued that population collapses in North America throughout colonization were not due mainly to lack of Native immunity to European disease. Instead, he claims that "When severe epidemics did hit, it was often less because Native bodies lacked immunity than because European colonialism disrupted Native communities and damaged their resources, making them more vulnerable to pathogens." In specific regard to Spanish colonization of northern Florida and southeastern Georgia, Native peoples there "were subject to forced labor and, because of poor living conditions and malnutrition, succumbed to wave after wave of unidentifiable diseases." Further, in relation to British colonization in the Northeast, Algonquian speaking tribes in Virginia and Maryland "suffered from a variety of diseases, including malaria, typhus, and possibly smallpox." These diseases were not solely a case of Native susceptibility, however, because "as colonists took their resources, Native communities were subject to malnutrition, starvation, and social stress, all making people more vulnerable to pathogens. Repeated epidemics created additional trauma and population loss, which in turn disrupted the provision of healthcare." Such conditions would continue, alongside rampant disease in Native communities, throughout colonization, the formation of the United States, and multiple forced removals, as Ostler explains that many scholars "have yet to come to grips with how U.S. expansion created conditions that made Native communities acutely vulnerable to pathogens and how severely disease impacted them. ... Historians continue to ignore the catastrophic impact of disease and its relationship to U.S. policy and action even when it is right before their eyes."^[6]

Historian David Stannard says that by "focusing almost entirely on disease ... contemporary authors increasingly have created the impression that the eradication of those tens of millions of people was inadvertent—a sad, but both inevitable and "unintended consequence" of human migration and progress," and asserts that their destruction "was neither inadvertent nor inevitable," but the result of microbial pestilence and purposeful genocide working in tandem.^[102] He also wrote:^[103]

...Despite frequent undocumented assertions that disease was responsible for the great majority of indigenous deaths in the Americas, there does not exist a single scholarly work that even pretends to demonstrate this claim on the basis of solid evidence. And that is because there is no such evidence, anywhere. The supposed truism that more native people died from disease than from direct face-to-face killing or from gross mistreatment or other concomitant derivatives of that brutality such as starvation, exposure, exhaustion, or despair is nothing more than a scholarly article of faith...

In contrast, historian Russel Thornton has pointed out that there were disastrous epidemics and population losses during the first half of the sixteenth century "resulting from incidental contact, or even without direct contact, as disease spread from one American Indian tribe to another."^[104] Thornton has also challenged higher Indigenous population estimates, which are based on the Malthusian assumption that "populations tend to increase to, and beyond, the limits of the food available to them at any particular level of technology."^[105]

The European colonization of the Americas resulted in the deaths of so many people it contributed to climatic change and temporary global cooling, according to scientists from University College London.^[106][107] A century after the arrival of Christopher Columbus, some 90% of Indigenous Americans had perished from "wave after wave of disease", along with mass slavery and war, in what researchers have described as the "great dying".^[108] According to one of the researchers, UCL Geography Professor Mark Maslin, the large death toll also boosted the economies of Europe: "the depopulation of the Americas may have inadvertently allowed the Europeans to dominate the world. It also allowed for the Industrial Revolution and for Europeans to continue that domination."^[109]

• Indigenous peoples in Canada
• Native Americans in the United States
• History of Native Americans in the United States
• List of Indian massacres
• List of Indian reserves in Canada by population
• List of Indian reservations in the United States
• Amazonas before the Inca Empire
• American Indian Wars
• Classification of indigenous peoples of the Americas
• Conquest of the Desert
• Genocide of indigenous peoples
• Genocides in the Americas
• Guatemalan genocide
• Selknam genocide
• Smallpox epidemics in the Americas
• Trail of Tears
• Indigenous peoples
• Uncontacted peoples
• Racism in Canada#Indigenous peoples
• Racism in North America
• Racism in South America
• Racism in the United States#Native Americans