The period that is considered the early stone age and took place between 2.7 million bce and 10,000 bce is called the

Paleolithic Era.

The first humans evolved in Africa during the Paleolithic Era, or Stone Age, which spans the period of history from 2.5 million to about 10,000 BCE.

president thomas jefferson commissioned the expedition shortly after the louisiana purchase in 1803 to explore and to map the newly acquired territory, to find a practical route across the western half of the continent, and to establish an american presence in this territory before britain and other european powers