By 10,000 BCE, humans were relatively well-established throughout North America. Originally, Paleo-Indians hunted Ice Age megafauna like mammoths, but as they began to go extinct, people turned instead to bison as a food source. As time went on, foraging for berries and seeds became an important alternative to hunting. Paleo-Indians in central Mexico were the first in the Americas to farm, starting to plant corn, beans, and squash around 8,000 BCE. Eventually, the knowledge began to spread northward. By 3,000 BCE, corn was being grown in the valleys of Arizona and New Mexico, followed by primitive irrigation systems and early villages of the Hohokam.^[5]

One of the earlier cultures in the present-day United States was the Clovis culture, who are primarily identified by the use of fluted spear points called the Clovis point. From 9,100 to 8,850 BCE, the culture ranged over much of North America and also appeared in South America. Artifacts from this culture were first excavated in 1932 near Clovis, New Mexico. The Folsom culture was similar, but is marked by the use of the Folsom point.

A later migration identified by linguists, anthropologists, and archeologists occurred around 8,000 BCE. This included Na-Dene-speaking peoples, who reached the Pacific Northwest by 5,000 BCE.^[6] From there, they migrated along the Pacific Coast and into the interior and constructed large multi-family dwellings in their villages, which were used only seasonally in the summer to hunt and fish, and in the winter to gather food supplies.^[7] Another group, the Oshara tradition people, who lived from 5,500 BCE to 600 CE, were part of the Archaic Southwest.