The earliest people in the Americas probably were Asians who crossed the prehistoric land bridge across the Bering Strait. They were largely of Mongoloid ancestry.
President Jefferson sent a couple of his representatives over to France to buy the city of New Orleans. What he got was the Louisiana Purchase, a patch of land that nearly doubled the size of the young nation.
Prehistoric peoples entered what is now Nevada as early as 11,000 years ago, and the region was probably continuously inhabited.