1491: New Revelations of the Americas Before Columbus

Charles Mann's 1491 is a superb history of the Americas prior to Columbus, full of all kinds of interesting information showing that Native American societies were more complicated, more diverse, and in certain ways more advanced than is typically assumed. They built large cities — the total population across the Americas was potentially 90 million to 112 million — and many societies were extremely advanced technologically, especially with regard to food production and the genetically-engineered creation of critical crops such as maize, squash and beans. Highly recommended.