North Americans have always been immigrants, and for the first Americans the New World was a land of abundance. Cooler, less seasonal, and more thickly forested than today, it contained a wide variety of species. Living off the land, the incoming peoples branched into diverse cultures.
After Columbus's "discovery" of the New World, Europeans arrived, devastating the Native Americans, drawing borders, and clashing with each other. While its people continue to change the land and immigrants continue to arrive, this vast, ancient continent is still very much alive.