Since the glaciers receded, the rich lands of the Mississippi River Valley have always attracted mankind. Here cultures grew and evolved, each borrowing from the previous, eventually culminating in a new civilization archaeologists have named Mississippian. Hello, I'm Jim Wilhelm.
This is the center of what was once the largest city in North America. Today we know it as Cahokia, sometimes called City of the Sun, and it might also be called the pinnacle of the Mississippian culture. Located at the confluence of three rivers, whose waters provided both food and transportation, Cahokia reached an estimated population of 20,000 people by 1150 A.D., which was larger than London at the time. It was a city complete with suburbs, plazas, and markets.
Now keep in mind that there were many permanent Mississippian settlements scattered throughout North America. But this one was by far the largest and most influential. Most of the population lived in small thatched huts arranged in family neighborhoods. Rising over the huts were a number of mounds, some used as platforms for the homes of the elite, a visual reminder of the city's social order. The city included 120 mounds, of which 80 remain today.
It was the largest and grandest of them all. It was a city center in more ways than one. There lived the chieftain who was both the ruler and the spiritual leader of the population.
It covers more than 14 acres and rises in four terraces to a height of 100 feet, making it the largest prehistoric earthen structure in the Western Hemisphere. Core samples indicate that varying textures of soil were used to assure proper drainage. Just imagine, for hundreds of years, generations carried baskets of dirt from huge borrow pits to make this mound. The work began before the Vikings discovered the New World, and was finished just after the Second Crusades. Looking at the mounds and artist renditions, it's easy to make comparisons to similar structures in Mexico, but there's no evidence that the Mississippian culture ever had contact with people that far south.
Today, visitors can do what was unimaginable to the people of Cahokia. Today, ordinary people can come up those recently refurbished stairs and enjoy the view that was once available only to the highest of the elite. We're at the top of the largest mound from which the chieftain could survey his city.
But he was more than a political ruler. He was also recognized as the brother of the sun. Archaeologists have determined that a large building once stood here.
It was a place where religious rites and administrative duties were thought to have occurred. Nobody's really sure because this was a prehistoric society. What that means is that they had no written language.
But the real driving force behind Cahokia's success was not its ruling class, but this. Corn. Somehow the Mississippian culture had developed a knowledge of how to raise this prolific crop in large fields. With the stable food supply, the population grew. Consequently, the city organizations, their beliefs, and technology became more complex.
In addition, the extra food could be used as trade within the city or with other communities. For example, during excavations, archaeologists discovered mica from the Smoky Mountains, seashells from the Gulf of Mexico, and copper from the North. From these materials, artists would create decorative pieces and jewelry to sell in the city.
What archaeologists have learned about these people is explained here at the Interpretive Center. Inside, displays explore the history of the city, the beliefs of its inhabitants, and speculation about daily life. The most common structure in the village was a small thatched-roof hut where one family lived. Family ties were very important, and it's thought that several generations would cluster together, forming small, self-sufficient neighborhoods. They had their own facilities, like sweat lodges to cleanse body and mind, plus elevated granaries.
The poles were coated to prevent insects from entering. And the sides were sealed with a mixture of grass and clay. But it was far from an idyllic life.
In reality, the population worked to support the elite class. Commoners would spend their lives in the fields or in the burrow pits, while the fruits of their labor were enjoyed by the hierarchy. In 1961, while excavating a site for a proposed new highway, archaeologists discovered what has since been called the American Woodhenge. Set in a giant circle were 48 treated cedar poles, a solar calendar used to chart the seasons and to determine the planting and harvest times.
In fact, at the beginning of each new season, the rising sun lined up with a specific pole. The calendar was aligned so that during the all-important spring and fall equinox, the sun would appear to rise directly over the chieftain's mound. This was quite fitting, since as you'll recall, he was known as the brother of the sun.
Eventually, it was discovered that over time there had been five such circles, each larger than the previous, and each time the number of poles increased by 12. Why 12? And why increase the size? It's just another mystery of Cahokia.
To unravel those mysteries, archaeological work continues. This is Mound 72, one of only six of this type of mound here at Cahokia. It's called a ridgetop mound.
It was originally excavated in the early 60s, but recently it has been revisited. To everyone's amazement, Mound 72 actually covered three smaller burial mounds. And inside one of those was found the remains of a possible chieftain, laid to rest on a bed of 20,000 shell beads, plus the remains of six of his retainers. In another section are the remains of 300 people, more than half of which were young women who had been sacrificed. Interestingly, some of the bodies were found not in the mound, but under the mound, using the mound itself as a grave marker.
Now keep in mind when visiting, not all the mounds here were used for burials. Most were used as platforms to raise buildings. And this type of burial was only for the elite. Common folks were buried in the ground outside the city. Another interesting aspect of the city is that it was a planned community.
Pathways connected the public areas to neighborhoods. The mounds were built around a central plaza where games were played with much bedding. Welcome back to Cahokia, where it's estimated that the height of its population occurred at about 1150 A.D. at 20,000 people. Yet 150 years later, this site lay abandoned.
Why is one of the largest mysteries of this city. Also at the time of Cahokia's height, a stockade was quickly erected around the central area, protecting the major religious center along with some of the homes of the highest officials. Was there worry over riots, or disputes over food distribution, or threats from an enemy?
Without a written language, it's hard to know exactly what happened. But it's thought that a combination of things brought about the demise of Cahokia. For example, the climate was changing. The growing season was becoming shorter.
Excavation shows that an over-dependency on corn in the diet led to poor nutrition. Plus, for miles around, all the trees had been removed for fuel and building materials, driving the wildlife away and allowing silt to close streams. Plus, it was a densely populated area, perhaps as many as 4,000 people per square mile.
Imagine all the waste that would have produced. Plus, there might have been competition for available living space. All of these things together could have contributed to the demise of Cahokia.
Today the paths of Cahokia are still in use, but now by curious visitors who wander among the remains of this once affluent city. This is also the only place in Illinois that has been designated a World Heritage Site by the United Nations. For more information about Cahokia, call the Interpretive Center at 618-346-5160.