The Mississippian world

Between 1000 and 1450 there were hundreds of towns along the rivers of eastern North America, built around flat-topped earthen pyramids. The largest, Cahokia, was in the twelfth century bigger than London. Four hundred years later all of it was gone, and the Europeans who arrived believed the country had always been empty.

What a town looked like

The core was an open plaza with one or more mounds around it. The mounds were flat on top, and there stood the temple or the chief's house — placed high because height meant rank. Around the plaza lay residential districts, fields of maize, beans and squash, and often a palisade.

Everything was carried. No draught animals, no wheels, no metal tools. Monks Mound at Cahokia holds around 620,000 cubic metres of earth, brought there in baskets of some fifteen kilograms.

Timeline

900

maize becomes the staple crop in the Mississippi valley

1050

Cahokia grows explosively; the city is laid out almost at once

1100

Cahokia probably holds 15,000–20,000 people, more than contemporary London

1200

Cahokia begins to empty; the palisade is built and rebuilt

1250

Moundville in Alabama and Etowah in Georgia at their height

1350

Cahokia is abandoned

1400

the Mississippian world persists in the south and east, but without a centre

1539–1543

de Soto's expedition meets the system working

1600s

most of the mound towns are gone

What kind of society

Not a state. What existed were chiefdoms: hereditary leaders with religious authority, able to demand labour and tribute from surrounding villages, but without a civil service or an army in any modern sense. They shared religious motifs — a falcon warrior, a sun cross, a coiled serpent — across an area larger than western Europe, but that no more makes them one kingdom than Gothic cathedrals make medieval Europe one.

Why they vanished

Cahokia empties long before Europeans arrive, and the explanations are several: deforestation and flooding, drought documented in tree rings, internal conflict — the palisade was built five times — and perhaps that a system resting on a chief's personal authority is fragile by nature.

For the rest of the culture the answer is simpler and worse. De Soto's expedition of 1539 is the only eyewitness account we have of these societies functioning. The expedition brought pigs and diseases with it. When the French reached the same country a hundred and fifty years later, the towns were gone.

The story that filled the gap

In the nineteenth century it was widely believed in the United States that the mounds had been built by a vanished "mound builder race" — Phoenicians, Vikings, Israelites, anyone but the ancestors of the people then being displaced. The Smithsonian's systematic survey under Cyrus Thomas refuted this conclusively in 1894. The myth persisted for decades regardless, because it was useful.