Overview

When Europeans reached North America's shorelines in the late 1400s and began to explore the continent's interior in the 1500s, they saw the vast land as a source of new plants, animals, and minerals for them to use and to transport back to Europe. As they colonized this New World, they also brought with them many familiar plants and animals for food, farming, and other purposes. This exchange of species between the two continents had positive and negative effects, and they continue today. On the positive side, the exchange introduced what would become important agricultural crops and beneficial animals to both continents. It also, however, expanded the range of species that carried disease and competed with beneficial native species, and it...