The Cahokia Mounds (also simply known as Cahokia ; Smithsonian trinomial ID 11 MS 2) is the site of a Native American city which existed c. 1050 – c. 1350 AD, directly across the Mississippi River from present-day St. Louis. The state archaeology park lies in south-western Illinois between East St. Louis and Collinsville. The park covers 2,200 acres (890 ha; 3.4 mi2; 8.9 km2), and contains about 80 manmade mounds, but the ancient city was much larger. At its apex around 1100 AD, the city covered about 6 square miles (16 km2), included about 120 earthworks in a wide range of sizes, shapes, and functions, and had a population of between 15,000 and 20,000 people.
Cahokia was the largest and most influential urban settlement of the Mississippian culture, which developed advanced societies across much of what is now the Central and the Southeastern United States, beginning around 1000 AD. Today, the Cahokia Mounds are considered to be the largest and most complex archaeological site north of the great pre-Columbian cities in Mexico.
The city's original name is unknown. The mounds were later named after the Cahokia tribe, a historic Illiniwek people living in the area when the first French explorers arrived in the 17th century. As this was centuries after Cahokia was abandoned by its original inhabitants, the Cahokia tribe was not necessarily descended from the earlier Mississippian-era people. Most likely, multiple indigenous ethnic groups settled in the Cahokia Mounds area during the time of the city's apex.
Cahokia Mounds is a National Historic Landmark and a designated site for state protection. It is also one of the 26 UNESCO World Heritage Sites within the United States. The largest pre-Columbian earthen construction in the Americas north of Mexico, the site is open to the public and administered by the Illinois Historic Preservation Division and supported by the Cahokia Mounds Museum Society. In celebration of the 2018 Illinois state bicentennial, the Cahokia Mounds were selected as one of the Illinois 200 Great Places by the American Institute of Architects Illinois component (AIA Illinois). It was recognized by USA Today Travel magazine, as one of the selections for 'Illinois 25 Must See Places'.
History
Historical overview
Although some evidence exists of occupation during the Late Archaic period (around 1200 BCE) in and around the site, Cahokia as it is now defined was settled around 600 CE during the Late Woodland period. Mound building at this location began with the emergent Mississippian cultural period, around the 9th century CE. The inhabitants left no written records beyond symbols on pottery, marine shell, copper, wood, and stone, but the evidence of elaborately planned community, woodhenge, mounds, and burials later in time reveal a complex and sophisticated society.
Cahokia became the most important center for the Mississippian culture. This culture was expressed in settlements that ranged along major waterways across what is now the Midwest, Eastern, and Southeastern United States. Cahokia was located in a strategic position near the confluence of the Mississippi, Missouri, and Illinois Rivers. It maintained trade links with communities as far away as the Great Lakes to the north and the Gulf Coast to the south, trading in such exotic items as copper, Mill Creek chert, shark teeth, and lightning whelk shells.
Development (9th and 10th centuries)
In the centuries preceding 1000 CE, American Bottom populations were living in small settlements of 50 to 100 people that were used for short durations of 5–10 years. At least two of these larger clusters were present at Cahokia, one dating to the mid-7th and 9th centuries. Later in time, many began to be constructed along cosmologically organizing principles, emphasizing cardinal directions and distinct sectors of society. By the end of the 10th century, many of these settlements aggregated into larger groups. These larger villages included the earlier cosmogram layouts complete with large central posts, pits, and/or structures.
An extensive nucleated community sprawled across 35–70 hectares (86–173 acres) in Cahokia proper, with its beginnings at the end in the late 900s CE. By this time it seems a few thousand people were living in the American Bottom region. Moundbuilding activity may have occurred at Cahokia proper but certainly did at one site to the north near Horseshoe Lake. These Late Woodland people were farmers but maize's importance at this time was marginal. Its successful introduction occurred around 900 CE. Most of the crops grown at the time were from the Eastern Agricultural Complex suite, an older and endemic farming tradition.
Rise and peak (11th and 12th centuries)
In the years around 1050 CE, the city-proper's three urban precincts: St. Louis, East St. Louis, and Cahokia were constructed. At the same time, an ordered city grid—oriented to the north along the Grand Plaza, Rattlesnake Causeway, and dozens of mounds—was imposed on earlier Woodland settlements. This was accompanied by a homogenization of material culture (e.g. pottery and architectural styles) that divided the smaller settlements beforehand. Mound construction increased across the region in the 11th century in the floodplain and, for the first time, in the uplands to the east. Some mounds were built on earlier settlement locations—arguably by descendants emphasizing their particular ancestral positions in the new social order. All villages experienced either renewal and construction efforts turning them into mound centers, or were depopulated to become just a few households or a single farmstead. New settlement types including nucleated settlements, mound centers, small dispersed clusters of houses, and single-family farmsteads appeared throughout the region.
The city's complex construction of earthen mounds required digging, excavation and transportation by hand using woven baskets. Construction made use of 55 million cubic feet (1.6 million cubic meters) of earth, and much of the work was accomplished over decades. Its highly planned large, smoothed-flat, ceremonial plazas, sited around the mounds, with homes for thousands connected by laid out pathways and courtyards, suggest the location served as a central religious pilgrimage city.
At the high point of its development, Cahokia was the largest urban center north of the great Mesoamerican cities in Mexico and Central America. Home to about 1,000 people before circa 1050, its population grew rapidly after that date. According to a 2007 study in Quaternary Science Reviews, "Between AD 1050 and 1100, Cahokia's population increased from between 1,400 and 2,800 people to between 10,200 and 15,300 people", an estimate that applies only to a 1.8-square-kilometre (0.69 sq mi) high-density central occupation area. As a result of archeological excavations in the early 21st century, new residential areas were found to the west of Cahokia; this discovery increased estimates of historic area population. Archaeologists estimate the city's population at between 6,000 and 40,000 at its peak. If the highest population estimates are correct, Cahokia was larger than any subsequent city in the United States until the 1780s, when Philadelphia's population grew beyond 40,000. Its population in the 12th century may have been larger than that of London and Paris.
Studies of Cahokia's rise see large-scale immigration as an essential contributor to the city's initial rapid growth. At the onset of the "Big Bang," non-local ceramics begins to appear in higher frequencies across site types indicating interaction or immigration from populations around the lower Ohio Drainage (Yankeetown), Lower Mississippi Valley (Coles Creek), Upper Midwest (below), and south-central plains (Caddo). Many of these immigrants moved into outlying villages in the eastern uplands, referred to as the Richland Complex. Intensive farming and textile production occurred in these villages which has been interpreted as supplicant behavior directed towards the central urban core of the city. The novel practices these immigrant communities brought with them have been argued as essential to the creation of the character of Cahokia as a city. One such example, the common mound-and-plaza pairing, was adopted from longstanding Coles Creek organizational principles.
Contacts across the mid-continent and possibly beyond are attested to have reached a peak between 1050 and 1150 CE. Mill Creek chert from southwestern Illinois, most notably, was used in the production of hoes, a high demand tool for farmers around Cahokia and other Mississippian centers. Cahokia's loose control over distribution, though not production, of these tools was important in emphasizing a new agricultural regime. Mississippian culture pottery and stone tools in the Cahokian style were found at the Silvernale site near Red Wing, Minnesota, and materials and trade goods from Pennsylvania, the Gulf Coast, and Lake Superior have been excavated at Cahokia. Cahokians traveled down to the Carson site in Coahoma County, Mississippi and built a settlement during the 12th century. Others paddled upriver to the site of Trempleau Bluffs in southern Wisconsin, to create a mounded religious center at the end of the 11th century.
It was during the Stirling phase (1100–1200 CE) that Cahokia was at its height of political centralization. Current academic discourse has emphasized religion as a major component in consolidating and maintaining the political power essential to Cahokia's urbanity. The Emerald Acropolis mound site in the uplands, was a site where the moon, water, femininity, and fertility were venerated; the mounds were aligned to lunar events in its 18.6 year cycle. Immigrant ceramics early in the archaeological record argue that it was central in attracting immigrants as pilgrims. Political control was exercised in the Cahokian hinterlands at distinctive temple complexes consisting of T or L shaped structures and sweatlodges. Distinctive rituals have archaeologically documented at these complexes involving tobacco, red cedar, agricultural produce, and female Cahokian flint clay figurines. Intense public rituals, like the sacrifice of dozens of women at mound 72 and interment of powerful leaders in ridge top mortuary mounds, integrated populations in shared experiences and narratives of their world during the 11th and 12th centuries.
One of the major problems that large centers like Cahokia faced was keeping a steady supply of food, perhaps exacerbated by droughts from CE 1100–1250. A related problem was waste disposal for the dense population, and Cahokia is believed to have become unhealthy from polluted waterways. Because it was such an unhealthy place to live, Snow believes that the town had to rely on social and political attractions to bring in a steady supply of new immigrants; otherwise, the town's death rate would have caused it to be abandoned earlier.
Decline (13th and 14th centuries)
By the end of the 12th century, two distinct events marked the beginning of Cahokia's rearticulation and decline. Circa 1160–1170 CE. a large walled residential compound in the East St. Louis precinct was burned down. Multiple ritual structures that were filled with an unusual density of stone tools, exotic materials, and pots filled with shelled maize were included in this burning. The event possibly represented unrest in response to 12th century inequalities. The same area was later rebuilt but not for residential purposes. In the same general timeframe around 1175 CE, people constructed the first iteration of the large central palisade around Cahokia's core. People began leaving the city in larger numbers beginning in the late 12th century. In the middle of the succeeding 13th century, Cahokia's population had decreased by half if not more, and by 1350 CE the city was abandoned.
Scholars have proposed environmental factors, such as environmental degradation through overhunting, deforestation and pollution, and climatic changes, such as increased flooding and droughts, as explanations for abandonment of the site. However, more recent research suggests that there is no evidence of human-caused erosion or flooding at Cahokia.
The late 12th century into the turn of the 13th (the Moorehead phase, 1200–1300 CE) was one of change. People stopped constructing and using the earlier T and L shaped ritual buildings as well as large circular rotundas. Family homes were built larger and storage pits previously located outside of them were moved inside. Ceramic styles and production techniques shifted with an increase in plates, cord-marking, and solar-themed iconography. There was also an increase in cemeteries of grouped minor-elites outside of Cahokia. Though mound construction still occurred, it did so at a lesser rate. Many earlier mounds were ritually capped and ceased to be modified afterwards. Altogether, this has been taken as a time when centralized political structures were weakening and religious practices thought essential were re-evaluated.
Political, economic, or cultural problems may also have contributed to the community's decline. Thomas Emerson and Kristin Hedman argue that Cahokia's large immigrant population was a factor in the city's ultimate fragmentation, as differing languages, customs, and religions obstructed the creation of a cohesive Cahokian cultural identity. Analyses of Cahokian burial sites and the associated remains have also shown that many Cahokians were not native to the city or its immediate surrounding region. These immigrants were sometimes buried separately from native residents, a possible indicator of weak integration along ethnic lines. It is likely that social and environmental factors combined to produce the conditions that led people to leave Cahokia.