Up until very recently it was believed that in 1491, the year before Columbus landed, the Americas, one-third of the earth's surface, were a near-pristine wilderness inhabited by small roaming bands of indigenous people.

But recently unexpected discoveries have dramatically changed our understanding of Indian life. Many scholars now argue that the Indians were much more numerous, were in the Americas for far longer and had far more ecological impact on the land than previously believed. This knowledge has enormous implications for today's environmental disputes, yet little has filtered into textbooks and even less into public awareness.

Mann brings together all of the latest research, and the results of his own travels throughout North and South America, to provide a new, fascinating and iconoclastic account of the Americas before Columbus.