Cahokia mounds


At a time when settlements in the Americas rarely exceeded 400 or 500 inhabitants, the Native American center of Cahokia was as large as contemporary London, a size that no other city in the United States would attain until the nineteenth century. The well-organized aggregation of mounds and residential districts had a population estimated at 10,000 to 30,000—some sources claim 40,000. Cahokia’s distinctive earth mounds (there were 120 of them) took three forms: conical, “ridge top,” and, most commonly, platforms, often crowned with ceremonial buildings or the houses of the powerful. At the heart of the city stood the huge ceremonial embankment (now known as Monks Mound) that was in itself a stupendous feat of planning and engineering.

The indigenous American civilization known as Mississippian—no one knows what they called themselves—sprang up in the American Bottom, an extensive fertile floodplain near the confluence of the Mississippi, Missouri, Illinois, Kaskaskia, and Meramec Rivers. Between about a.d. 1000 and 1250, they lived near what is now central and East St. Louis and where the Illinois towns of Fairmont City, Dupo, Lebanon, and Mitchell now stand. This suburban concentration was eclipsed by their greatest achievement: Cahokia, dubbed “America’s lost metropolis.” Cahokia was named for the branch of the Illinois people who occupied the region in the seventeenth century, long after the builders had departed.

In terms of both agriculture and trade, Cahokia was perfectly located. The predictable annual flooding of farmland enabled planning and replenished the soil so that maize and other crops were sustainable for centuries. The river systems reaching out to much of North America facilitated trade, and there is evidence of commercial traffic over a network that extended from Minnesota in the north to Mississippi in the south; Cahokian traders reached west as far as Kansas and east to Tennessee. Raw materials such as copper, seashells, and mica were imported and processed in Cahokia to be exported as copper ornaments and shell beads—indications of a sophisticated manufacturing industry. It was once believed that this productive economic environment led to population growth, as Cahokian civilization slowly flowered.

Recently, archeologist Timothy Pauketat has questioned this conclusion, claiming that there is no evidence for it. Although not all his peers agree, he suggests that Cahokia experienced an urban implosion in little more than a decade early in the eleventh century a.d., growing from a village of only 1,000 into a city ten times that size. Based on studies of wider Native American beliefs, that event may have been due to the emergence of a charismatic chief whose arrival prompted villagers to abandon their