Based on the latest scientific findings, this breakthrough book argues that most of what we thought we knew about the Americas before Columbus was wrong. In the last 20 years, archaeologists and anthropologists equipped with new scientific techniques have made far-reaching discoveries about the Americas. For example, Indians did not cross the Bering Strait 12,000 years ago, as most of us learned in school. They were already here. Their numbers were vast, not few. And instead of living lightly on the land, they managed it beautifully and left behind an enormous ecological legacy. In this riveting, accessible work of science, Charles Mann takes us on an enthralling journey of scientific exploration. We learn that the Indian development of modern corn was one of the most complex feats of genetic engineering ever performed. That the Great Plains are a third smaller today than they were in 1700 because the Indians who maintained them by burning died. And that the Amazon rain forest may be largely a human artifact. Compelling and eye-opening, this book has the potential to vastly alter our understanding of our history and change the course of todays environmental disputes.