It was one of the largest cities in the world. At its peak in 1200 CE it covered more than six square miles and had a population of 30,000–larger than contemporary London or Moscow or Paris. No city in the United States would match it until after the Revolutionary War. Yet the city of Cahokia, near modern-day St Louis, is today unknown and forgotten–mostly because it was a Native American city.
Monk’s Mound, Cahokia Photo from Wiki Commons
The ruins of Cahokia lie just across the Mississippi River from the modern city of St Louis. It consists of a series of artificial earthen mounds, some over 100 feet tall, built laboriously by hand, one basketful at a time. There may have been over 120 separate mounds during Cahokia’s heyday–today only around 80 of them remain.
Because the inhabitants of Cahokia had no written language, we know very little about them today. Not even their actual names: the name “Cahokia” comes from a local band of Native Americans who were living in the area during the European invasion, centuries after Cahokia was abandoned by its builders. Today, all we know about the Cahokia mound builders comes from archaeological excavation.
The earliest known artificial earthen mounds in North America are found in northeastern Louisiana, and date to about 5,500 years ago, a time known to archaeologists as the “Archaic Period”. By the time of the Woodland Period, from about 500 BCE to 800 CE, more extensive mounds began to appear in Ohio. Some of these mounds were burial sites; others seem to have been artificial platforms for religious ceremonies, and were built in the shapes of animals. Their presence indicates that the people who built them were not nomadic bands of hunter-gatherers, but lived settled agricultural lives.
By 1000 CE, a village had formed at the Cahokia site. The floodplains of the Mississippi River must have been very fertile, and Cahokia turned into an agricultural village with several thousand inhabitants. Similar villages have been found from St Louis to Memphis: they farmed squash, beans, corn, amaranth, and sunflowers. Known as the “Mississippian Culture”, it is not known what connection they had to any of the existing Native American nations.
Around 1050 CE, there was a drastic change at Cahokia. What had until then been a typical agricultural village, was now transformed into a city, with a regular plan and roads. Archaeological evidence shows that a number of dwellings were torn down, several areas of hilly land were leveled out. Construction began on a series of huge artificial mounds, made from rammed earth, with flat plaza areas around them. The largest of these is the “Monk’s Mound”. With four terraces, standing 92 feet tall, the Monk’s Mound is the largest earthen pyramid in North America. At the top there was a large temple or hall made from post logs up to three feet in diameter and measuring over 100 feet long. The plaza surrounding the mound was set off by a palisade fence with over 20,000 wooden posts. Other smaller mounds radiated away from the Monk’s Mound in all directions. In all, the mounds contained at least 55 million cubic feet of soil, carried into place in wicker baskets.
Located a short distance to the west of Monk’s Mound was a “Woodhenge”, a large circle of standing logs. This was rebuilt several times over the centuries, containing from 12 to 60 pillars, which were aligned with the solstices and equinoxes. A smaller Woodhenge was also found some distance away, near a mound known as Mound 72. Here, archaeologists excavated the skeleton of a man in his forties, buried along with thousands of sea shell beads and hundreds of finely-made arrowheads–he was perhaps a chief or leader. With him were four young men who were missing their hands and skulls, and over 50 young women–assumed to be sacrificial victims. Around the mound, some 200 more human skeletons were found, buried in groups over a long period of time. They are also believed to be sacrificial victims. A number of statues found in Cahokia depict a female goddess with field crops and a large snake–perhaps a fertility goddess to whom sacrifices were made.
Between the mounds were neighborhoods of small dwellings, with thatch roofs and walls made from woven saplings. Recovered artifacts show that they made pottery, farmed, fished on the Mississippi River, and worked copper into jewelry and utensils. At Mound 34, a copper workshop was found–craftsmen apparently used large stones mounted on tree stumps as anvils, and stone hammers and tools to work the copper. Several of the finished copper pieces had been annealed in a fire.
The Cahokians seem to have had an extensive trade network. Archaeological sites have been found as far as 500 miles away, in Wisconsin, that have Cahokia-style pottery, hoe blades, and flat stone discs used in a game called “chunkey”. Within Cahokia itself have been found copper ore from Michigan, sea shells from the Gulf of Mexico, and chert stone from South Carolina.
Around 1160 CE, a wooden palisade fence with protective towers was built completely encircling Cahokia. At this time, the city was at its height, and contained perhaps as many as 40,000 inhabitants. But after this, the city began to decline. We do not know why: it may have been ecological changes that made it impossible to support the city’s population, it may have been a threat of conflict with neighboring people; it may have been political collapse. Whatever the reason, by 1250 the city’s population was only a few thousand, and by 1300 it was completely abandoned.
In the early 1700’s a group of French Trappist monks found the site and established a monastery nearby (giving their name to Monk’s Mound).
Over the next 200 years, the mounds were mostly neglected. As the nearby cities of East St Louis and Collinsville, Illinois, grew, they encroached into the area. Many of the mounds were destroyed, and even today there are buildings and streets within the mound complex. In 1923 most of the surviving mounds were designated a State Park, and later a State Historical Site, but in the 1950’s the Federal Government put an interstate highway right through the area. That led to an increased interest in archaeological excavations at the site, and in 1964 Cahokia was listed as a National Historic Site. In 1982, the United Nations UNESCO designated Cahokia as a World Heritage Site.