Cahokia

Based on Wikipedia: Cahokia

America's Forgotten Metropolis

In the year 1100, while London was a muddy town of perhaps ten thousand souls and Paris not much larger, a city on the banks of the Mississippi River held somewhere between fifteen and forty thousand people. It sprawled across six square miles of carefully planned neighborhoods, ceremonial plazas, and towering earthen pyramids. It was the largest urban center north of Mexico, and it would remain the largest city in what is now the United States until Philadelphia surpassed it in the 1780s—nearly seven centuries later.

We don't know what its inhabitants called it.

Today we call it Cahokia, borrowing the name from an unrelated tribe that lived nearby when French explorers arrived in the 1600s. By then, the great city had been abandoned for three hundred years, its monuments gradually being swallowed by vegetation, its story already lost to living memory.

The Big Bang

For centuries before Cahokia's rise, people had lived in the region known as the American Bottom—the broad floodplain where the Mississippi, Missouri, and Illinois rivers converge just east of present-day St. Louis. They gathered in small settlements of fifty to a hundred people, farming crops from what archaeologists call the Eastern Agricultural Complex: native plants like sunflowers, goosefoot, and squash that had been domesticated thousands of years earlier in North America.

Maize—corn—arrived around 900 CE, imported from Mexico through centuries of trade networks. It was a game-changer. Corn produces more calories per acre than almost any other crop, and it stores well through winter. But for a century after its introduction, life in the American Bottom continued much as before.

Then, around 1050 CE, something extraordinary happened.

Archaeologists call it the "Big Bang," and the name is apt. In what seems to have been a remarkably short period—perhaps a single generation—Cahokia transformed from a modest cluster of villages into a planned urban center. Workers laid out a massive central plaza, oriented precisely to the cardinal directions. They began constructing enormous earthen mounds that would eventually number over 120. They established a grid of pathways and courtyards connecting thousands of homes. They did all of this by hand, carrying the earth in woven baskets, ultimately moving fifty-five million cubic feet of soil.

The population exploded. Estimates suggest Cahokia went from perhaps one thousand inhabitants before 1050 to over ten thousand within fifty years. Some researchers believe it eventually reached forty thousand—a number that, if accurate, would have made it one of the largest cities on Earth at the time.

Who Built This City?

The people who created Cahokia left no written records, at least none that we can read. They left symbols carved on pottery and shells, painted on wood and copper, but these remain largely undeciphered. What we know comes from what they left behind: their buildings, their trash, their dead.

What the archaeological evidence reveals is that Cahokia was built by immigrants as much as by locals. Pottery styles from the lower Ohio Valley, the lower Mississippi, the upper Midwest, and the south-central plains all appear in the archaeological record right around the time of the Big Bang. People came from across a vast region—drawn by something.

But drawn by what? This is where interpretation becomes tricky. Some researchers emphasize religion—the pull of a sacred center where pilgrims came to participate in rituals. Others focus on politics and economics—the opportunities available in a growing urban hub that controlled trade networks spanning half a continent. Most likely, as with great cities throughout history, the answer involves all of these factors intertwined.

What we can say with some confidence is that many of these immigrants settled in satellite communities in the uplands east of Cahokia proper. Archaeological evidence suggests they engaged in intensive farming and textile production, possibly as tribute to the urban center. They brought new practices that became central to Cahokian identity—including the distinctive pairing of mounds with plazas, a pattern borrowed from the Coles Creek culture of the lower Mississippi Valley.

Monks Mound and the Urban Core

The most striking feature of Cahokia is Monks Mound, the largest pre-Columbian earthwork north of Mexico. It rises one hundred feet above the surrounding plain, covers fourteen acres at its base, and contains an estimated twenty-two million cubic feet of earth—all of it carried by hand. A massive building once stood at its summit, probably the residence of Cahokia's paramount chief.

But Monks Mound was just the centerpiece of an urban complex that included two other major precincts: one at the site of present-day East St. Louis and another across the river where St. Louis now stands. (Much of the western precinct was destroyed during the construction of St. Louis in the nineteenth century, its mounds leveled for fill dirt and building material.)

The central area around Monks Mound featured a Grand Plaza covering some forty acres—roughly the size of thirty-five football fields. This wasn't wild space; it was engineered. Workers scraped away the natural topography, filled in low spots, and created a level surface that may have hosted markets, ceremonies, or both. Raised causeways connected different parts of the city, and a series of wooden posts—which archaeologists have dubbed "Woodhenge"—marked astronomical alignments with the rising and setting sun.

Trade Networks and Material Culture

Cahokia sat at the most important crossroads in North America. The Mississippi provided a highway running from the Gulf of Mexico to the upper Midwest. The Missouri reached deep into the Great Plains. The Illinois connected to the Great Lakes region. Whoever controlled this junction controlled continental trade.

The evidence of long-distance exchange is scattered throughout Cahokian archaeological sites. Copper from the Great Lakes. Marine shells from the Gulf Coast. Shark teeth from the Atlantic or Gulf. A distinctive type of stone called Mill Creek chert from quarries in southwestern Illinois, worked into agricultural hoes that were traded throughout the Mississippian world.

Cahokia's influence extended far beyond trade goods. Archaeologists have found Cahokian-style pottery and tools at sites in Minnesota. Cahokians established a settlement in Coahoma County, Mississippi, and built a mounded religious center in southern Wisconsin. The city wasn't just a hub—it was the cultural center of a civilization that stretched across much of eastern North America.

Religion, Power, and Human Sacrifice

One of the most disturbing discoveries at Cahokia came from a mound designated simply as "Mound 72." Excavations in the 1960s and 1970s revealed mass graves containing the remains of over 270 people, most of them young women who appear to have been sacrificed.

The central burial in Mound 72 was a man laid out on a platform of twenty thousand marine shell beads arranged in the shape of a falcon or thunderbird. Near him were buried caches of precious objects: arrowheads made of exotic stone, polished stones used for a game similar to shuffleboard, and sheets of mica from the Appalachian Mountains. This was clearly someone of enormous importance.

The sacrificed women were buried in pits nearby. Some appear to have been killed elsewhere and reburied; others may have been killed on the spot. The sheer scale of the sacrifice—unprecedented in the archaeological record of North America—speaks to both the power of Cahokia's rulers and the intensity of its religious life.

Religious ceremonies seem to have been central to maintaining Cahokia's political order. At a satellite site called the Emerald Acropolis, mounds were aligned to track the 18.6-year cycle of the moon. Temple complexes throughout Cahokia's hinterland featured distinctive T-shaped and L-shaped buildings where rituals involving tobacco, red cedar, agricultural produce, and female figurines took place. These ceremonies, performed across a wide region, helped create a shared Cahokian identity that transcended the diverse ethnic backgrounds of the city's inhabitants.

The Crisis of the Twelfth Century

Cahokia reached its peak of political centralization during what archaeologists call the Stirling phase, from roughly 1100 to 1200 CE. But even at its height, the city faced serious problems.

Feeding a population of ten to forty thousand people in pre-modern conditions was an enormous challenge. The surrounding floodplain was fertile, but droughts are documented for the period between 1100 and 1250 CE. Waste disposal presented another crisis: with so many people living in close quarters, waterways became polluted. Archaeological evidence suggests that life in Cahokia was actually quite unhealthy, with mortality rates high enough that the city required a constant influx of new immigrants just to maintain its population.

Around 1170 CE, something dramatic happened in the East St. Louis precinct. A large walled residential compound was burned down, along with multiple ritual structures that had been deliberately filled with valuable objects—stone tools, exotic materials, pots full of corn. Whether this represents a revolt, an invasion, a ritual destruction, or something else entirely remains unclear. But it marked a turning point.

Shortly afterward, around 1175 CE, workers constructed a massive wooden palisade around Cahokia's ceremonial core. This wall, with its watchtowers and defensive features, suggests that Cahokia's rulers now feared attack—from enemies within, enemies without, or both.

Decline and Abandonment

The thirteenth century saw Cahokia's gradual dissolution. The distinctive ritual architecture—the T-shaped buildings, the circular rotundas—fell out of use. Ceramic styles shifted, with an increase in plates and solar-themed imagery replacing earlier designs. Family homes were built larger, with storage pits moved inside rather than shared in common areas. These changes suggest a society turning inward, with centralized political structures weakening and communal practices giving way to more family-centered life.

By the mid-1200s, Cahokia's population had fallen by at least half. The immigrants who had once flocked to the upland villages were among the first to leave. Many headed south, into the Cairo Lowlands of southern Illinois and the Central Mississippi Valley. Others eventually made their way to the Cumberland Basin in central Tennessee. Finely crafted artifacts that had been made in Cahokia—copper plates worked in a technique called repoussé, engraved shells—began appearing at rising centers like Moundville in Alabama and Etowah in Georgia, suggesting that Cahokian craftspeople or their techniques had dispersed across the Southeast.

By 1350 CE, Cahokia was empty.

Why Did Cahokia Fall?

The collapse of Cahokia has generated theories for over a century. Early explanations focused on environmental degradation: overhunting, deforestation, pollution, and flooding caused by erosion. More recent research, however, has found little evidence of human-caused erosion at Cahokia, suggesting that environmental explanations may be too simple.

Climate change almost certainly played a role. The droughts of the twelfth and thirteenth centuries would have stressed agricultural systems and may have contributed to the social unrest visible in the archaeological record. But other Mississippian centers thrived during this same period, so climate alone cannot explain Cahokia's unique trajectory.

Some researchers emphasize the role of warfare. Burned villages dating to the thirteenth century appear throughout the Illinois River Valley north of Cahokia. Palisades—defensive walls—become common across the Midwest and mid-South during this period, as communities consolidated into more defensible settlements. An invasion or series of raids could have disrupted Cahokia's trade networks and undermined its authority.

Perhaps the most compelling recent explanation focuses on Cahokia's diversity. Thomas Emerson and Kristin Hedman have argued that the city's large immigrant population—while essential to its rapid growth—may have undermined long-term stability. With residents speaking different languages, following different customs, and practicing different religions, the creation of a cohesive Cahokian identity was always a struggle. The intense public rituals of the eleventh and twelfth centuries—including human sacrifice—may have been attempts to forge unity through shared spectacle. When those rituals lost their power to bind the population together, the centrifugal forces of diversity pulled the city apart.

What Cahokia Tells Us

The story of Cahokia challenges easy narratives about pre-Columbian North America. This was not a simple society of small tribes living in harmony with nature. It was a complex urban civilization with monumental architecture, long-distance trade networks, elaborate religious practices, social stratification, and all the problems that come with concentrated power—including pollution, inequality, and political violence.

It rose with remarkable speed, achieved remarkable scale, and then—like so many cities throughout history—declined and was abandoned. The Maya cities of Central America, the Roman cities of North Africa, the Khmer cities of Cambodia all share similar arcs. Urban civilizations are fragile things, dependent on complex systems of food production, trade, governance, and shared belief that can unravel when stressed.

What makes Cahokia particularly poignant is how thoroughly it was forgotten. When European colonizers arrived in North America, they could not believe that indigenous peoples had built the great mounds scattered across the eastern half of the continent. They invented elaborate theories about lost races of "mound builders"—anyone except the ancestors of the people they were displacing. It took archaeology to prove what should have been obvious: that the monuments were built by the ancestors of indigenous Americans, and that those ancestors had created civilizations as sophisticated as any in the world.

Today, Cahokia Mounds is a state historic site and a UNESCO World Heritage Site, one of only twenty-six in the United States. It covers 2,200 acres and preserves about eighty of the original mounds. Most visitors experience it as a peaceful park, its ancient plazas now covered with grass, its former neighborhoods now farmland. But those who climb Monks Mound and look out over the Mississippi Valley can still sense something of what once was: the greatest city in North America, built by people whose names we will never know, for reasons we can only guess.