It was populated.

It was networked.

It was home to peoples who had been living on this continent for thousands of years before Kennewick Man was born.

This last point is crucial, because it gets to the heart of one of the most explosive questions that his discovery raised: where had the first Americans come from, and when?

The traditional scientific view, as it stood in the 1990s, held that the first humans arrived in North America from Asia, crossing a land bridge that existed across what is now the Bering Strait during the last Ice Age — the strip of land called Beringia.

This migration was thought to have happened roughly twelve to fifteen thousand years ago, just as the ice sheets were beginning to melt and corridors through the ice were opening up to allow southward movement.

This model — called the Clovis First hypothesis, after the distinctive spear points found at a site in Clovis, New Mexico, that were long thought to represent the oldest human presence in the Americas — had been the dominant framework in American archaeology for decades.

But by 1996, it was already under serious challenge.

Sites were being found across both North and South America that appeared to predate the Clovis horizon.

Genetic studies were beginning to suggest that the peopling of the Americas was more complex than a single migration through Beringia.