For most of the twentieth century, the dominant model for the first peopling of the Americas — the Clovis-first hypothesis — held that Clovis people were the first Americans.

Under this model, people crossed from northeastern Asia into Alaska via the Bering land bridge when sea levels were low enough to expose the broad grassy plain called Beringia, then moved southward through a corridor that opened between the retreating Laurentide and Cordilleran ice sheets as the glaciers began to melt, and eventually spread across the continent with a speed and geographic breadth that the distribution of Clovis sites seemed to support.

This model was attractive, relatively well-supported by the evidence that had accumulated by the mid-twentieth century, and widely taught.

It had a satisfying narrative clarity: the first Americans came from Asia, crossed a land bridge, developed Clovis technology, spread across the continent, and became the ancestors of the diverse Native American peoples who would eventually be encountered by European explorers.