The Population of the Americas in 1492 is Disputed

A view of the island of Hispaniola in the Caribbean from the International Space Station. Historical demographics tries to look down on past societies from space, but there are always a lot of clouds in the way. https://en.wikipedia.org/wiki/Hispaniola#/media/File:ISS027-E-17333_-_View_of_Dominican_Republic.jpg

After an email exchange, I have learned that some prominent people want to believe that the population of the Americas in 1492 is known closely. Here is why I say it is debated within a factor of 20.

Colin McEvedy and Richard Jones have the following to say in their 1978 Atlas of World Population History:1

The estimate of 1m Amerindians north of the Rio Grande- which breaks down into 0.2m in Canada, 0.05m in Alaska, and 0.75m in the rest of the Continental USA- goes back at least as far as J. Mooney (Smithsonian Miscellaneous Collections 80.7 (1928)); it seems to be generally accepted, though the California school of revisionists has issued a trial balloon in favour of 20m (sic). The present population of 0.6m represents a recovery from the all-time low of 0.5m reached in 1925. … The size of the population of Mexico in 1492 has lately become the subject of much academic argument. … The point at issue is this: was the population of Mexico in 1492 no more than 5m (Rosenblat) or was it more than 30m (Cook and Borah)? Comparisons with other parts of the world at comparable levels of culture leads us to throw in our lot with Rosenblat.

So McEvedy and Jones acknowledge disputes about the pre-Columbian population of the USA and Canada within a factor of 20, and disputes about the population of Mexico within a factor of 6. Their arguments for one end of the range are no more sophisticated than “it seems to be generally accepted” and that if the population of Mexico had as high as 30 million, then the rate of decline which this implies would be an “improbability.” Most of their numbers for the period 1 to 1500 CE were copied by Angus Maddison whose numbers are very widely used today. But 1978 is a long time ago, so if you prefer you can check a more recent survey.

The introduction of European diseases caused much of North America to revert from fields and parkland to secondary forest, because the people who had been burning the brush to encourage deer or clearing forest to grow maize died or fled. Alexander Koch and colleagues wanted to guess how this impacted the world system, so they tried to estimate the population of the Americas in 1492.2 They began by surveying the literature and found a wide range of estimates:

• 2.2 to 52 million for Central Mexico (factor of 24)
• 2.3 million to 13 million for Yucatan (factor of 6)
• 1 to 20 million in Amazonia (factor of 20)
• 0.9 to 18 million in the USA and Canada (factor of 20)

They could not see any way to decide who was correct with the resources available to them and decided to take their omnium gatherum, assume the guesses reflected a statistical distribution, and find the middle of that distribution (“We included all the prior studies and did not make any judgement on their relative quality.”) Their study was published in 2023. So both quick-and-dirty researchers in the 1970s, and a careful literature review in 2023, find estimates that differ by a factor of 6 to a factor of 20.

Continue reading if you want some concise, impassioned, but less organized thoughts.

Can’t New Methods Help?

As David Henige pointed out on 1998, most of these estimates start with numbers in the writings of early travellers or the records of colonial and post-colonial states.3 There are many reasons to question these numbers, such that sometimes a number in one story is based on a number in another story not a count, or that by the time any settler made a count many of the natives had been killed by disease, forced labour, expulsion from their homelands into wasteland, and plain old murder. Researchers then add, multiply, divide, and subtract the numbers in their sources until they feel right. One name for these numbers is decorative statistics. There has been no great improvement in these methods during my or my parents’ lifetime, although certainly sometimes a new source is discovered or archaeological work affects the arithmetic.

Most people who become historians or historical demographers are not great with numbers. Most academics who use statistics professionally are not as competent as statisticians wish they were either. Methods used to estimate historical populations remind me of being a teenaged worldbuilder and TTRPG gamemaster, they are often painstaking but involve long chains of reasoning from dubious premises. Those are the politest things I can say on this subject without spoiling a beautiful summer evening. Timothy W. Guinnane goes through some of the problems with McEvedy and Jones’ methods at length.4

Given enough money and labour and equipment, archaeologists can survey large regions for evidence of settlements before European contact. This kind of research only covers a few areas, it works best for people with durable houses and pottery, and converting counts of potsherds or potholes to people is very difficult. It can be hard to tell the difference between a very large village, and a village where it was customary to rebuild your house in a new location every time the old one decayed. Aztec archaeologists like Michael E. Smith seem unsure whether they can yet give these kinds of numbers for Central Mexico, let alone the Northern Woodlands of Canada.5

It is well known that when you ask people to give you a number for something, and there is a plausible minimum but no maximum, the numbers will be skewed upwards by people with big imaginations. Counts of First Nations and American Indian populations in the early 20th century generally provide a minimum for the pre-contact population of North America, although even then there are difficulties because the reintroduction of the horse and the spread of native and Old World crops let people live in places where few of them had lived before. The indigenous peoples of the Americas were not timeless or static, they tried new ways of living and responded to new challenges and opportunities. But it is easier to guess arbitrarily high numbers than arbitrarily low numbers, and so any attempt to take an average or a median will skew high.

In some cases, different numbers reflect different theories. There seems to be an active debate whether large areas of Amazonia were farmed in 1492, leaving the so-called terra preta or enriched black earth, or whether the peoples of Amazonia were mostly hunters and fishers who kept a few gardens like people in western Brazil today. In these cases, picking a number in between the two theories is more likely to be wrong than siding with one.

There are almost no ways of telling whether any of these guesses are right or wrong. In ancient Afro-Eurasia, the only societies where we have good data are the Greco-Roman world, Egypt, and Han China. We can estimate the population of those societies within say a factor of 3 using contemporary censuses and very detailed archaeology. Evidence for those societies is no help in estimating the population of Hispaniola (Hati and the Dominican Republic) or Newfoundland in 1492, because the ways they lived and were organized were totally different. None of these societies faced waves of unfamiliar diseases, then was conquered and brutally exploited or just forced off their lands into places that newcomers had no use for yet, so we can not use them to decide how much indigenous populations should have declined in that scenario.

Needless to say, this is a brutally emotional and partisan topic, because to ask “how many people lived in the Americas in 1492?” is to ask “how great an atrocity was the European settlement of the Americas?” Bartolomé de las Casas in 1542 said that the Indians had once been very numerous to help convince Philip of Spain that the surviving Indians needed protection. Attempts to count indigenous people have involved methods such as giving them a tag and a number because learning their names was too much trouble, and the purposes of counts have included forced labour and knowing when to kidnap their children. Government decisions about who is indigenous do not always agree with indigenous decisions. As an ancient historian writing a blog post I can not discuss this with the sensitivity it deserves, but in Canada there are many First Nations, Inuit, and Metis groups who can give you their takes.

I believe it is possible to spiral closer to the truth in some parts of this question. I do not believe that it will ever be possible to get estimates of world population in 1492 and trust them like you would trust a Statistics Canada report. And even if it is knowable in principle, I don’t think that will stop educated people from coming up with higher and lower estimates, and thoughtful people believing them. As far as I can tell, the population of the Americas in 1492 is disputed by a factor of 20.

Why Didn’t I Know This?

If you are interested in world history but thought we knew the population of Canada in 1492 within a factor of 2, you were probably lead astray by confident talkers and writers who give one number, wave their hands about their methods, and sound very serious and professional. The uncomfortable details are hidden in the appendices and footnotes. Economists in particular seem more comfortable working with a single ‘best guess’ than dealing with ranges of uncertainty or different scenarios. The abstract of Alexander Koch’s study emphasizes the middle range of their population estimate not the wide range in their sources (and Koch and colleagues explain why its hard to know historical populations, but you have to read the whole article to see their explanation). Very few people who read a press release or a piece of science writing want to dive in to colonial tax reforms or the details of statistical methods, so PR teams and science writers try not to talk too much about different conclusions you could draw from the same evidence.

Those of us who have looked at the evidence and don’t see any way to talk about the population of most of the world before the 19th century don’t tend to write about it. Life is short and its hard to get “we cannot know that” through peer review or into a trade press. So figures for the population of the Americas in 1492 tend to circulate in print among the epistemologically optimistic, while skeptics just tell you “I see no way to know” if you ask them. Most people who want a number grab a number provided by the optimists, whether a “high count” or a “low count.” Understanding why these numbers are not trustworthy requires a lot of careful, concentrated attention and most people are busy.

And some people feel very righteous in declaring that the population of the Americas was big (so settlement was a big atrocity) or small (so settlement was tragic for the victims but no bigger a tragedy than a small war in China). Righteousness does not encourage people to talk about uncertainties, assumptions, and the best arguments for other points of view. I am a righteous seeker of the truth, but I hope I have explained why I believe what I believe.

(scheduled 19 July)

1. Colin McEvedy and Richard Jones, Atlas of World Population History (1978) https://archive.org/details/atlasofworldpopu0000mcev/ The quotes come from pages 289 and 292 of the edition on the Internet Archive. ↩︎
2. Alexander Koch et al., “Earth system impacts of the European arrival and Great Dying in the Americas after 1492,” Quaternary Science Reviews, Volume 207, 1 March 2019, Pages 13-36 https://doi.org/10.1016/j.quascirev.2018.12.004 I thank John Mashey for the reference. ↩︎
3. David Henige, Numbers from Nowhere: The America Indian Contact Population Debate (University of Oklahoma Press: Norman, NB, 1998) ↩︎
4. Timothy W. Guinnane, “We Do Not Know the Population of Every Country in the World For the Past Two Thousand Years,” The Journal of Economic History, Vol. 83, Issue 3 (2023) pp. 912-938 https://doi.org/10.1017/S0022050723000293 ↩︎
5. Michael E. Smith, “Comment: Income and inequality in the Aztec Empire on the eve of the Spanish conquest” https://pubpeer.com/publications/063084EB3B247130A804B2BD326F2E# ↩︎