What Columbus didn't find

Native Village 2005
Charles C. Mann, author of  "1491: New Revelations of the Americas Before Columbus," says that much of what we learned in school is not the whole story.  Among his points:
When Christopher Columbus invaded the New World in 1492, more people inhabited the Americas than lived in Europe;
The largest Aztec city — Tenochtitlán, the site of modern-day Mexico City — was more populous than Paris;
Unlike European cities, Tenochtitlán had running water and clean streets;
At least 4,000 years ago, Mesoamerican farmers developed maize (which led to today's corn) from wild plants into a staple crop. No one understands how they did it. "Somebody who did that today would win a Nobel Prize," said Nina V. Federoff, a geneticist from Pennsylvania State University;
The Inca, Maya, Toltec and others operated on a continental scale spanning many generations;
Indians cleared forests with fire, irrigated and terraced vast farmland, and built cities and temples — producing ingenious technology and culture as well as devastating wars and deforestation.

  Germs killed more native people than war. Unlike Europeans, the Indians had no immunities to the diseases;
European diseases followed Francisco Pizarro's march against the Incas and Hernando Cortes' invasion of Aztec Mexico;
Measles, cholera and smallpox epidemics followed Native traders and messengers who unknowingly carried the germs back to their homelands;
In the early 15th century, Hernando De soto's four year expedition through the Southeast saw hordes of people lining the Mississippi River. 100 years later, Sieur Robert Cavelier de La Salle canoed down the same stretch of river and found no trace of man;
De Soto didn't see buffalo, but La Salle found them everywhere, filling the ecological void left by the missing people. "That's one reason whites think of Indians as nomadic hunters," said UCLA anthropologist Russell Thornton. "Everything else — all the heavily populated urbanized societies — was wiped out."