What was the impact of Iberian conquest and settlement on the peoples and ecologies of the Americas?

Before Columbus's arrival, the Americas were inhabited by thousands of groups of indigenous peoples with distinct languages and cultures. These groups ranged from hunter-gatherer tribes organized into tribal confederations to settled agriculturalists to large-scale empires connecting bustling cities and towns. The best estimate is that the peoples of the Americas numbered between 35 and 50 million in 1492. Their lives were radically altered by the arrival of Europeans.

The growing European presence in the New World transformed its land and its peoples forever. Violence, forced labor, and disease wrought devastating losses, while surviving peoples encountered new political, social, and economic organizations imposed by Europeans. Although the exchange of goods and people between Europe and the New World brought diseases to the Americas, it also gave both the New and Old Worlds new crops that eventually altered consumption patterns across the globe.