When Christopher Columbus made landfall in the Americas on Oct. 12, 1492, he encountered Indigenous Lucayans living on the Bahamian island now called San Salvador. Columbus wrote in his diary about "great multitudes of men" who greeted him that day, bartered with him and told him about other groups who lived on nearby islands.

But within a few decades after Columbus' arrival, the Indigenous people of the Americas were decimated by what anthropologist Eric Wolf called the "Great Dying" — a combination of epidemic disease, warfare and enslavement that led to a rapid decline in the Native population.

For centuries, researchers have been trying to figure out how many Indigenous people lived in the Americas just prior to the fateful arrival of European colonizers.

The answer to that question has been surprisingly elusive, and estimates based on historical censuses, archaeological sites and land carrying capacity in the Western Hemisphere have varied wildly.

Recent research into Native American demography has revealed that the population peaked several centuries before Europeans showed up on the shores of North America — and that if Europeans had arrived at that peak, the entire history of the continent may have been different.

Early estimates of the Indigenous population

People have lived in the Americas for at least 14,000 years, having entered the continents via the region around the Bering Strait. Archaeological evidence shows these first Americans dispersed throughout the newly encountered lands fairly quickly. But what happened to the population between that dispersal and the arrival of Columbus is a huge unknown; estimates of the number of Indigenous people living in the Western Hemisphere in 1492 have ranged from 1 million to 112 million people.

"We don't have good quantitative estimates," George Milner, an anthropologist at Penn State, told Live Science. "The numbers are all over the place."

One of the first modern researchers who attempted to quantify the Indigenous population prior to Columbus was anthropologist Henry Dobyns. In a 1983 book, Dobyns used estimates of how many people each type of landscape could support as well as historical records of 16th-century disease epidemics to arrive at an Indigenous population estimate of around 112 million people — more than 100 times larger than some previous experts had believed.

"In essence, Dobyns filled up the landscape to its maximum carrying capacity, so that all environmentally similar places were occupied by the same number of people," Milner said. "He also made the assumption that epidemic disease spread widely and universally, which would make sense if the landscape was filled up."

But a burst of archaeological research in the 1970s and 1980s revealed that the Americas were not uniformly settled, Milner said. Dobyns' estimates were therefore much too high.

Researchers then began to focus on creating population estimates for specific regions of the hemisphere, using techniques such as the relative density of pottery sherds at a site, the number of stone tools and flakes, the number and size of houses, and mortality trends from human skeletons.

In a 2019 study, geographers compiled 129 population estimates from 82 published studies to model the hemisphere-wide distribution of the Indigenous population in 1492. The researchers split the hemisphere into seven regions — the Caribbean, Mexico, Central America, Inca territory, Amazonia, North America and the rest of the Americas — and reached a combined estimate of 60.5 million. Their estimate for North America (modern-day Canada and the U.S.) was about 3 million to 6 million, less than one-third of Dobyns' estimate of 18 million.

A regional perspective – North America

The 2019 study found that the most populous groups in the Western Hemisphere in 1492 were the Aztecs, largely in modern-day Mexico; and the Inca, who lived along the west coast of South America.

But the people we know the most about from an archaeological standpoint are Indigenous groups in the U.S. and Canada.

In a 2010 study, Milner and geographer George Chaplin zoomed in on the data from eastern North America, compiling historic group sizes and sizes of archaeological occupation areas to estimate the location and size of "population aggregates." Using this method, their overall estimate for the eastern U.S. and southeastern Canada was about 1.6 million people.

"Our mean estimates," Milner and Chaplin wrote, "indicate that North America held roughly 2.8 to 5.7 million people" or a "best estimate" of 3.8 million people in the early 16th century, before European diseases dramatically decreased the size of the Indigenous population.

"If you want to start estimating specific populations, you should use measures that work across regions," Robert Kelly, an archaeologist at the University of Wyoming, told Live Science. "People produce things that can be carbon-dated everywhere, because everyone had to build fires for heat and for cooking."

Charcoal from hearths is one of the main human-made things that archaeologists use to radiocarbon-date a site. The radiocarbon data provides a range of dates showing when the firewood was likeliest to have been used.

In North America, many of those carbon-14 dates from charcoal, as well as from animal bones and plant remains from archaeological sites, have been entered into the Canadian Archaeological Radiocarbon Database (CARD).

In a 2009 study, Matthew Peros, a geographer at Bishop's University in Quebec, and co-authors mathematically combined the radiocarbon date ranges in CARD to generate a single curve that revealed how common C-14 dates were over time. At the time, CARD had about 25,000 records.

Because time periods with more people most likely produced more material that could be carbon-dated, the shape of the radiocarbon date curve gave the team an idea of when the population of North America increased and decreased.

They found that the population of North America increased rapidly around 50 B.C. and peaked around A.D. 1150. From that time until European contact, the Indigenous population may have been declining, possibly because of increased mortality from diseases like tuberculosis as people aggregated into denser settlements.

"The 1150 date was an interesting finding that also surprised us," Peros told Live Science. "I had assumed it would be more like 1500 just following the arrival of the Europeans."

In a 2025 study, Kelly and co-authors found a similar temporal peak. By that time, CARD's dataset had ballooned to over 100,000 dates, making the estimate more robust.

"Although devastated by European contact, the Indigenous population did not simply increase to a peak at 1500 CE and then decline," the researchers wrote in the study. In fact, they found evidence for a slight recovery in population numbers just prior to 1500.

But how large was that population? By combining the radiocarbon date curve with a starting population and factoring in average annual population growth, researchers can estimate the number of people living in North America around 1492, Peros said.

In their study, Peros and co-authors assumed that a handful of extended families — around 1,000 people — entered North America about 15,000 years ago as the founder population. With those inputs, the researchers estimated that the maximum population of North America was about 2.5 million in 1150 and had declined to about 1.8 million in 1492. But if people arrived significantly earlier than 15,000 years ago — which might be the case, given evidence from sites like White Sands in New Mexico, which dates to 23,000 years ago — or arrived in greater numbers, those population figures would be even higher.

"Had Europeans tried settling the continent at A.D. 1000, they would have run into a much, much larger Indigenous population," Kelly said. At that time, the city of Cahokia, near modern-day St. Louis, encompassed 6 square miles (16 square kilometers) and had a population of nearly 20,000 people.

"They could have fielded thousands of warriors, and it would have been a very different experience for the Europeans," Kelly said. "It could have been a very different history."

Why does this matter?

Experts told Live Science that the pre-1492 population of what is now the U.S. and Canada was between 2 million and 4 million. The archaeological deep dive in this region sets up the possibility that a full Western Hemisphere population estimate may be made someday.

Milner is optimistic they'll eventually get there. "Will it be done in my lifetime? Probably not," he said. "It's time-consuming, laborious and not especially flashy work to do."

Nonetheless, demography is important work, he said, because it can help us make estimates to prepare for the future.

"The world's population has more than doubled in my lifetime; that's unheard of in human existence," Milner said. "Environmental scientists are really trying to look at what's happened over long periods of time to give us a range of variation of what might happen in the future. We have to make some informed decisions about how to manage our landscape and accommodate these changes."

Understanding the number of Indigenous inhabitants in the Western Hemisphere in 1492 is also key to understanding the history of North America.

"North America was not an empty continent when the Europeans arrived," Peros said. "There were people and civilizations pretty much everywhere in the Americas for a long period of time. It is important for people to understand that when we talk about questions of reconciliation and when we do land acknowledgements."

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