Summary

Jonathan Haas, an archaeologist at the Field Museum of Natural History in Chicago, handed Mann a cloth that he said was 4,000 years old. It was soft and surprisingly well-made. They were standing at a dig on the central coast of Peru. Ruth Shady Solis, a Peruvian archaeologist, was leading the expedition. She had done work a few years back on a Peruvian site to the south that uncovered the oldest known city in the Americas. The new team determined that there were at least 25 cities buried in the mounds in the Norte Chico region. The team was focused on what was buried under the mound known as the Huaricanga mound. The dig revealed a temple that had at the time been the world’s largest buildings.

There were two ancient societies in South America that had gone largely unnoticed...