What They Found Inside America's Lost City Rewrites Everything — Cahokia

Just across the Mississippi River from modern St. Louis, there is a hill that shouldn't exist. It rises a hundred feet out of the Illinois floodplain in four broad terraces, its base larger than the Great Pyramid of Giza — and every ounce of it was carried there by hand, one woven basket of earth at a time. We call it Monks Mound. And it was only the center of something far bigger: a city. Around the year 1100, Cahokia was home to as many as 20,000 people. That made it larger than London at the same moment in history — and no city inside what is now the United States would grow that big again until Philadelphia, six centuries later. A true metropolis, with a downtown of more than 120 earthen pyramids, a Grand Plaza the size of dozens of football fields, organized neighborhoods, a trade network stretching from the Great Lakes to the Gulf, and a solar calendar of giant cedar posts that archaeologists nicknamed "Woodhenge." And then, within a few generations, every single person was gone. This is the full story of Cahokia — the greatest city of ancient America. We dig into what archaeologists found buried inside Mound 72: the "Birdman," laid out on a bed of more than 20,000 marine-shell beads, surrounded by evidence of mass ritual sacrifice. We lay out the real reasons the city may have collapsed — the two-mile defensive palisade rebuilt again and again, the catastrophic Mississippi floods, the deforestation of the surrounding hills, the shifting climate, and the crisis of faith that may have finally emptied the plazas — and we separate the solid evidence from the speculation. And we tell the uncomfortable truth about what happened next: how, for the better part of a century, European Americans refused to believe Native Americans could have built this, and invented a phantom "lost race of Mound Builders" — a comforting lie for a nation in the middle of taking a continent — until the Smithsonian's Cyrus Thomas demolished the myth for good in 1894. The people of Caho