"A study that radically alters our understanding of the Americas before the arrival of the Europeans in 1492." "Traditionally, Americans learned in school that the ancestors of the people who inhabited the Western Hemisphere at the time of Columbus's landing had crossed the Bering Strait twelve thousand years ago; existed mainly in small, nomadic bands; and lived so lightly on the land that the Americas was, for all practical purposes, still a vast wilderness. But as Charles C. Mann now makes clear, archaeologists and anthropologists have spent the last thirty years proving these and many other long-held assumptions wrong." "In a book that startles and persuades, Mann reveals how a new generation of researchers equipped with novel scientific techniques came to previously unheard-of conclusions."--BOOK JACKET.