There were millions of people living in the Americas when Christopher Columbus arrived in 1492. Columbus's voyage to what Europeans called the "New World" set the stage for the later European colonization of the Americas, with millions of emigrants (willing and unwilling) from the "Old World" eventually resettling in the Americas. While the population of Old World peoples in the Americas steadily grew in the centuries after Columbus, the population of the American indigenous peoples plummeted. The extent and causes of this population decline have long been the subject of controversy and debate, which became particularly widespread in 1992 during the 500th anniversary of Columbus's famous voyage, with a number of people claiming that the natives of the Americas have been the victims of genocide.
Estimates of how many people were living in the Americas when Columbus arrived have varied tremendously; in the 20th century scholarly estimates ranged from a low of 8.4 million to a high of 112.5 million persons. Given the fragmentary nature of the evidence, precise pre-Columbian population figures are impossible to obtain; estimates are often produced by extrapolation from comparatively small bits of data. In 1976, geographer William Denevan used various estimates to derive a "consensus count" of about 54 million people, although some recent estimates are lower than that.
Historian David Henige, representing a minority opinion, has argued that many population figures are the result of arbitrary formulas selectively applied to numbers from unreliable historical sources. He believes there is not enough solid evidence to produce population numbers that have any real meaning, and characterizes the modern trend of high estimates as "pseudo-scientific number-crunching."
This population debate has often had ideological underpinnings. Low estimates were sometimes reflective of European notions of their own cultural and racial superiority, as historian Francis Jennings has 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." At the other end of the spectrum, some have argued that contemporary estimates of a high pre-Columbian indigenous population are rooted in a bias against aspects of Western civilization and/or Christianity. Robert Royal writes that "estimates of pre-Columbian population figures have become heavily politicized with scholars who are particularly critical of Europe often favoring wildly higher figures."
Since civilizations rose and fell in the Americas before Columbus arrived, the indigenous population in 1492 was not necessarily at a high point, and may have already been in decline. Indigenous populations in most areas of the Americas reached a nadir by the early twentieth century, and in a number of cases started to climb again.