Period 1 begins with 1491. Of the American Indian population in what is now the United States was nearly 10 million before 1492, why is the United States population in modern times only 2 to 3% American Indian.

There are several reasons as to why the populations of the Native Americans dropped significantly after the arrival of the Europeans. The biggest reason for the decline in their populations were the diseases that the Europeans brought with them. The Native Americans didn't had an immune system that can cope with them, so they were rapidly dying out. Another reason were the wars, both between the Europeans and between each other, which took their toll and lot of people ended up dead. The living conditions also became much worse with the arrival of the Europeans as the tribes were pushed away from their lands and often were ending up in areas that didn't had enough food sources and water so again lot of them died.