Cahokia

The Cahokia Mounds, often simply called Cahokia, is the site of a large Native American city that thrived many years ago, from about 1050 to 1350 CE. It sat right across the Mississippi River from where the city of St. Louis stands today, in southwestern Illinois. This amazing place covers a huge area—about 2,200 acres or 3.5 square miles—and includes around 80 manmade mounds.

At its peak around the year 1100 CE, Cahokia was a busy city covering roughly 6 square miles. It had about 120 earthworks of many different shapes and sizes and was home to thousands of people. Cahokia was the largest and most important urban center of what is called the Mississippian culture, a group of advanced societies that lived across much of the Central and Southeastern United States starting around the year 1000 CE.

Today, the Cahokia Mounds are recognized as very important. They are the largest and most complex archaeological site found north of the big ancient cities in pre-Columbian Mexico. The area is protected as a National Historic Landmark and is one of the UNESCO World Heritage Sites within the United States. People can visit Cahokia Mounds, which is open to the public and cared for by the Illinois Historic Preservation Division. It’s a wonderful place to learn about the impressive civilizations that lived there long ago.

History

Historical overview

A map showing approximate areas of various Mississippian and related cultures. Cahokia is located near the center of this map in the upper part of the Middle Mississippi area.

Cahokia was a big city built by Native American people around 600 CE. It became the most important place for the Mississippian culture. This culture spread along rivers in the Midwest, Eastern, and Southeastern United States. Cahokia was near where the Mississippi, Missouri, and Illinois Rivers meet, which made it a good spot for trade. People there traded things like copper, shell tools, and shark teeth with places far away, from the Great Lakes to the Gulf Coast.

Development (9th and 10th centuries

Before the year 1000 CE, people in the area lived in small villages that they used for just a few years. By the late 900s CE, these villages grew bigger and were built in special ways that matched their religious beliefs. People farmed more, growing crops like maize, which became very important.

Rise and peak (11th and 12th centuries

Around 1050 CE, Cahokia grew very fast. The city had large ceremonial mounds and plazas, and thousands of people lived there. It was the largest city north of Mexico. People from many places moved to Cahokia, bringing new ideas and traditions. The city was important for religion and trade, with strong links to other areas.

Decline (13th and 14th centuries

Mississippian period showing the multiple layers of mound construction, mound structures such as temples or mortuaries, ramps with log stairs, and prior structures under later layers, multiple terraces, and intrusive burials

By the late 1200s, Cahokia began to decline. Many people left the city, and by 1350 CE, it was abandoned. Scholars think that problems like drought, flooding, and not enough food may have caused this decline. There were also changes in how people lived and believed, which might have made it hard to keep the city together.

Abandonment and resettling (15th through 19th centuries

After Cahokia was abandoned, the area was mostly empty until the 1600s when new groups of people arrived. The mounds built by Cahokia’s people were still there, and later settlers, including French colonists, saw them. As the city of St. Louis grew, many of these mounds were destroyed. Over time, people started to study the site to learn about its history.


Table	900–1050 CE	1050–1100 CE	1100–1200 CE	1200–1300 CE	1300–1600 CE
Archaeological Chronology	Terminal Late Woodland Period	Lohmann Phase	Stirling Phase	Moorehead Phase	Sand Prairie Phase
Developments	Villages nucleate and grow in size. Eastern Agricultural Crops cultivated. Maize introduced.	Urbanization and non-local contacts increase. Religious rituals and administrative centers appear. Greater Cahokia precincts and upland villages in the Richland Complex settled.	Moundbuilding continues. As does religious administration in the hinterlands. A large conflagration in the East St. Louis precinct circa 1160–1170 CE marks the beginning of depopulation.	Upland villages are depopulated. The entire city's population contracts. Storage pits moved inside residences. Marked change in ceramic styles. Non-local contacts are maintained.	Population continues to decline. The city is abandoned by 1400 CE with brief Oneota reoccupation.
Architectural record	Earliest earthen platforms. Villages organized around central feature as cosmograms.	Woodhenge, T-and-L-shaped structures, large circular and rectangular platform mounds, plazas, and causeways.	Continued construction of mounds. The first iteration of the central palisade is constructed circa 1175 CE.	Select mound construction. Termination of certain structures. Large rotundas and T-and-L-shaped structures are no longer constructed. The palisade is rebuilt.	Any possible small-scale mound construction ceases before 1400 CE.

Contemporary usage (post 19th-century)

Museum and Interpretive Center

Cahokia is very important to many Native American peoples today. Tribes such as the Osage Nation, Cherokee, Choctaw, Chickasaw, and Muscogee-Creek honor the site and keep traditions alive, such as building mounds. Many visit Cahokia for ceremonies and dances, and it inspires art and literature.

The Cahokia Museum and Interpretive Center welcomes many visitors each year. Cahokia is important for learning and research. Universities have studied the site since the 1960s. It was named a National Historic Landmark in 1964 and a World Heritage Site by UNESCO in 1982, which helps protect it and brings more support for studies.

Agriculture

Cahokia was surrounded by rich lands where people grew many types of food. Maize was an important crop, but people also ate goosefoot and sumpweed from the Eastern Agricultural Complex.

Researchers are not sure how Cahokia’s farming affected the land. Some think the soil may have become too poor. Others think the farming methods were gentle and kept the soil healthy.

The city thrived during a warm time called the Medieval Warming Period, when crops like maize, beans, and squash grew well. Later, cooler times called the Little Ice Age coincided with the city’s decline.

Notable features

The Cahokia Mounds were a big city of the Native American people, across the Mississippi River from St. Louis. The site had 120 earthen mounds spread over 6 square miles, but only 80 remain today. Thousands of workers moved a lot of earth to build mounds and community plazas.

Monks Mound, the largest structure, covers 14 acres and rises 100 feet high. The city had a well-planned layout with plazas and a special pathway called the Rattlesnake Causeway. The central district had a wooden fence with towers for protection. Beyond the main area, up to 120 more mounds were spread out, each with different purposes. The city’s neighborhoods were around plazas, with buildings made from poles and thatch. Researchers found a copper workshop and large timber circles known as Cahokia Woodhenge, used for tracking important dates in the year.

Artist's recreation of central Cahokia. Cahokia's east–west baseline transects the Woodhenge, Monk's Mound, and several other large mounds.

Main article: Monks Mound

Main article: Mound 72

Main article: Mound 34

Greater Cahokia

Cahokia was an important place for a big group of related sites. These sites included East St. Louis, St. Louis Mounds, Janey B. Goode, and the Mitchell site. Together, these places are called "Greater Cahokia" because they were all connected and worked together.

Related mounds

Until the 19th century, many mounds like those at Cahokia were in what is now St. Louis. Most were torn down for buildings, but a few are still there. One example is Sugarloaf Mound, which once marked the boundary between St. Louis and Carondelet. Another small mound can still be seen in O'Fallon Park.

One of the largest Mississippian sites is Kincaid Mounds State Historic Site, located in southern Illinois near the Ohio River. This site has 19 mounds and was an important place for leaders long ago. It is recognized as a National Historic Landmark.