The largest city in the Americas north of Mexico before European contact — a planned earthwork metropolis near modern St. Louis that rose around 1050 CE, held tens of thousands of people, and was abandoned within a few centuries, complicating the story that pre-contact North America held no cities.
A short drive from downtown St. Louis sits a flat-topped earthen mound bigger at its base than the Great Pyramid. People built it by hand, one basket of soil at a time. For three hundred years a city stood around it, then emptied. Most Americans have never heard its name. What does it mean that the largest city in early North America was forgotten, even as a myth grew that no such city ever existed?