The United States Lost Ancient Megacity of Cahokia: A Historical Rewrite | April 25, 2025

The Cahokia Mounds State Historic Site is the site of a pre-Columbian Native American city (which existed c. 1050–1350 CE) directly across the Mississippi River from modern St. Louis, Missouri. This historic park lies in southwestern Illinois between East St. Louis and Collinsville.

Things are quieter these days at Cahokia, now a placid Unesco site. But towering, earthen mounds there hint at the legacy of the largest pre-Columbian city north of Mexico.

A cosmopolitan whir of language, art and spiritual ferment, Cahokia’s population may have swelled to 30,000 people at its 1050 AD peak, making it larger, at the time, than Paris.

It’s what Cahokia didn’t have that’s startling, writes Annalee Newitz in their recent book Four Lost Cities: A Secret History of the Urban Age. The massive city lacked a permanent marketplace, confounding old assumptions that trade is the organising principle behind all urbanisation.

Lost Ancient Megacity of Cahokia
“Cahokia was a cultural centre rather than a trade centre. It still boggles my mind. I keep wondering ‘Where were they trading? Who was making money?’,” Newitz said. “The answer is they weren’t. That wasn’t why they built the space.”

Newitz isn’t alone in their surprise. Assumptions that commerce is the key to urban life-long shaped a Western view of the past, explains archaeologist Timothy Pauketat, who has studied Cahokia for decades.

“It’s a bias that influenced earlier archaeologists,” he said. When excavating cities in Mesopotamia, researchers found evidence that trade was the organising principle behind their development, then turned the same lens on ancient cities across the globe. “People thought that this must be the basis for all early cities. It’s led to generations of looking for that kind of thing everywhere,” Pauketat said.

They didn’t find it in Cahokia, which Pauketat believes may instead have been conceived as a place to bridge the worlds of the living and the dead. For many cultures with roots in ancient Cahokia, “water is this barrier between the world of the living and the world of the dead,” Pauketat said. Sprawling across a landscape that combines solid earth with patches of swamp, Cahokia may have served as a kind of spiritual crossroads.

Lost Ancient Megacity of Cahokia
“It’s a city built to straddle water and dry land,” Pauketat said. Living residents settled in the driest spots, while burial mounds rose in wetter places. Lidar scans of the site have revealed elevated causeways linking the “neighbourhoods” of the living and the dead, physical walkways that joined the realms.

And if living at the cusp of the two worlds sounds rather sombre, Cahokians seem to have seen their hometown as a festive place. In Four Lost Cities, Newitz writes that Cahokia’s planners crafted structures and public spaces devoted entirely to mass gatherings, where individuals would be swept up by the joy of collective experiences. The most spectacular of all was the 50-acre Grand Plaza, where 10,000 or more people could come together for celebrations in a monumental space flanked by earthen pyramids.

SEE NEXT PAGE