My Own True Love and I have put in thousands of miles over the years on I-55, the highway that leads from Chicago to Saint Louis. We’ve stopped at many historical sites–along the way and off the path. One of my all time favorites is Cahokia Mounds–the site of North America’s first city.

Our first visit to Cahokia was an eye-opener. Between 800 and 1400 CE, when Europe was struggling to find its way out of the Middle Ages, the area around modern St. Louis was the center of a great American civilization that neither of us had heard of. How had we missed something so important? *

The Mississippian culture was the most sophisticated prehistoric culture in the Americas north of Mexico. Mississippian sites have been found from Minnesota to Florida, but the culture’s heart was the settlement at Cahokia Mounds**, eight miles east of downtown St. Louis. At its height, around 1250 CE, Cahokia had an estimated population of 20,000 people, larger than London at the same time. The next North American city with a population that big was Philadelphia, 500 years later.

The Mississippians settled the area for the same reasons that European settlers built St. Louis. The convergence of the Mississippi, Missouri and Illinois rivers created a rich flood plain with good soil for farming and a wealth of hunting and fishing. The network of small waterways that fed into these rivers made travel easy. Three surrounding ecosystems–the Ozark Mountains, the prairies and the Eastern woodlands–provided a variety of raw materials.

Because they had a stable food supply, the Mississippians of Cahokia were able to support skilled craftsmen and trade for material and goods they could not make for themselves. Artifacts found at the site show craftsmanship well beyond the level of common household goods: stone statuettes in human and animal forms, dramatic effigy bottles and bowls and engraved copper plates of great beauty. In addition to local resources, artists had access to exotic materials traded over long distances: copper from the upper Great Lakes, mica from southern Appalachia, and seashells from the Gulf of Mexico.

The most obvious features of the Mississippian culture are the monumental earthen mounds. (This comes as no surprise, right?) Because the Mississippians had no draft animals, laborers carried the earth in baskets on their backs, 50 to 60 pounds at a time. Most of the mounds at Cahokia were flat-topped and served as the base for temples, chieftain’s houses, sweat lodges, council houses and charnel houses for the bones of rulers and heroes. Monks Mound*** is the largest of these, covering fourteen acres and rising in four terraces to a height of 100 feet.**** That’s roughly fifteen million baskets of earth.

Cahokia began to decline after 1250 CE, shrinking in both population and area. By 1400 CE, the city had been abandoned. Excavations show no signs of epidemic, invasion, or natural disaster to explain the city’s demise. As archeologists David Rindos and Sissel Johannessen describe it, “Cahokia didn’t collapse, it evaporated.”

The not-fall of Cahokia didn’t mean the end of Mississippian culture. When Fernando De Soto landed at Tampa Bay in 1539, he found flourishing Mississippian chiefdoms from Florida to the upper Tennessee River valley. The southeastern chiefdoms were decimated by European illnesses, but not destroyed. As late as the 1700s, the Natchez tribe of Louisiana lived in a village centered on a ceremonial plaza, with mounds at both ends and a temple containing the bones of its rulers:  Mississipian-lite.

If you’re interested in American prehistory–or history in general–add Cahokia Mounds State Historical Site to your must-see list. (Don’t take my word for it.  In 1982, Cahokia Mounds was named a UNESCO World Heritage site in 1982, joining the ranks of the Taj Mahal, the Great Wall of China, and the Grand Canyon as a world-class destination.)

* The same way we missed all kinds of historical stuff. Even at their best, our schools don’t do a good job of teaching us about history that doesn’t lead directly to us. Luckily we have the rest of our lives to poke around and fill in the gaps.

**Named after an Indian tribe who lived in the area in the seventeenth century. We don’t know what they called themselves because they left no written records. From a writer’s point of view, it’s a little dispiriting to realize that you can build a sophisticated culture without a written language.

***Named after French Trappist monks who gardened on the mound in the early 1800s. The danger of leaving no written records is that you get misleading names attached to your stuff.

****Roughly the height of a ten-story office building. The Great Pyramid at Giza covers thirteen acres and was 480 feet tall before erosion whittled it down.

Photographs courtesy of Cahokia Mounds State Historical Site.