The mound-building society that lived at Cahokia is one of America’s most famous — and mysterious — ancient civilizations. The Mississippian people thrived for centuries in what is now Illinois’ Mississippi River valley, just outside of St. Louis, until they mysteriously vanished sometime around 1400 A.D.
It's a tempting story, one that plays on the inherent romanticism of a "lost" civilization, and all its attendant drama. But archaeologists know that's not really the case. The people at Cahokia didn’t disappear — they more likely just relocated when conditions took a turn for the worse.
