In this groundbreaking work of science, history, and archaeology, Charles C. Mann radically alters our understanding of the Americas before the arrival of Columbus in 1492. Contrary to what so many Americans learn in school, the pre-Columbian Indians were not sparsely settled in a pristine wilderness; rather, there were huge numbers of Indians who actively molded and influenced the land around them. The astonishing Aztec capital of Tenochtitlan had running water and immaculately clean streets, and was larger than any contemporary European city. Mexican cultures created corn in a specialized breeding process that it has been called man's first feat of genetic engineering. Indeed, Indians were not living lightly on the land but were landscaping and manipulating their world in ways that we are only now beginning to understand. Challenging and surprising, this a transformative new look at a rich and fascinating world we only thought we knew.