The encounter between the peoples of eastern and western hemispheres that began nearly 500 years ago has had a dramatic effect on the way land and natural resources in the Americas are thought about and used. Exploration and colonization led to land use practices foreign to those developed by indigenous societies and compatible with the existing ecosystem. Almost 500 years ago, newcomers failed to learn from those who understood their home environment. The European campaign of "discovery" and conquest made this exchange impossible.