Across Beringia
Long before cities rose in Mexico or stone roads crossed the Andes, people entered the Americas from Asia. The leading explanation places early migrants on Beringia, a land bridge exposed when Ice Age sea levels fell across what is now the Bering Strait.
These Paleo-Indians were mobile hunter-gatherers, traveling in small bands of perhaps 20 to 50 extended-family members. As resources changed, they moved through new environments, eventually spreading across North and South America. Some groups may have traveled along the Pacific coast, while others used an interior corridor that became ice-free as the climate warmed.
A Debate Without a Final Answer
The timing remains unsettled. The Clovis culture has sites dating to about 13,000 years ago and was once treated as evidence of the earliest American settlement. Yet older sites, some dating to roughly 20,000 years ago, have been claimed. Genetic estimates have proposed an even broader range, from 40,000 to 13,000 years ago or earlier.
Two broad models organize the debate. The short chronology places the first movement south from Alaska around 14,000–17,000 years ago, followed by later waves. The long chronology proposes entry perhaps 30,000–40,000 years ago or earlier.
A Continent Transformed
By about 14,000 years ago, artifacts suggest that humans may already have reached Cape Horn at South America’s southern tip. Inuit ancestors arrived separately much later, likely moving from Siberia into Alaska across ice no more than about 2,000 years ago.
The remarkable implication is that a small number of ancient movements eventually produced an immense diversity of peoples. The first Americans did not simply occupy a continent—they adapted to and reshaped deserts, forests, coasts, plains, and mountains.