3.1: Reading/Media

Cahokia, an indigenous culture around 1050 CE near modern-day Collinsville, Illinois, was the most populous settlement in pre-Columbian North America. Scholars argue that both the vitality and the demise of Cahokia were tied to the culture's relation to water, set by the geologic landscape of the Mississippi floodplain. (Image from wikimedia.org.)

Watery Rituals on Mississippi Floodplain in Pre-Columbian America, 1,000 BP

Excerpts from "Cahokia as urban anomaly" by T. R. Pauketat, S. M. Alt, A. M. Betzenhauser, et al. Journal of Urban Archaeology 7, 253 (2023). CC BY-NC 4.0

The watery setting of Cahokia

Excerpt: After decades of debate over societal types and levels of complexity, many researchers have settled on recognizing the great, precolonial-era, Indigenous complex in the middle Mississippi River Valley—Cahokia—as some form of urbanism. On the one hand, this recognition is possible thanks to robust new archeological data on the scale, density, and hybridity of this extensive, tripartite, urban complex. These data point to a historical phenomenon that meets Louis Wirth’s (1938) criteria of ‘urbanism’—places that were large, dense, and heterogeneous. In other ways, Cahokia appears anomalous in North America if not the entire ancient world.

Cahokia’s known anomalous characteristics include its rapid emergence, its distanciated configuration, its unusual location, and its relatively brief florescence. Cahokia’s three quasi-distinct ‘precincts’ were built quickly using wood, thatch, and earth. They were also built astride and amid marshes and bodies of water, including the Mississippi River. Why this was the case may be rooted in the spiritual or affective powers of watery places. That is, Cahokians built their urban complexes atop or in alignment with what was undoubtedly an already animate or spiritually charged landscape. The people referenced fundamental elements, substances, atmospheric phenomena, and celestial bodies, as well as the movements and transubstantiations thereof, in ways that gave Cahokia vitality. Thousands of people flocked to it. Yet precinct locations amidst and astride marshy wetlands and bodies of water might have long-term negative consequences. In fact, two of the precincts, Cahokia and East St Louis, were built in what one famous visitor in 1842 regarded as an ‘ill-favoured’ stretch of muddy, hot, and humid Mississippi River flood-plain historically known in less-than-complimentary terms as the ‘American Bottom’. The Cahokians do not seem to have mitigated these so-called ill-favored attributes, and the entire urban experiment lasted but a century and a half. In the end, Cahokia’s ‘Mississippian’ descendants never attempted to recreate the scale, density, and heterogeneity of their founding.

Figure \(\PageIndex{1}\): The Greater Cahokia region, highlighting precincts,
sites, and localities mentioned in the text. (From Pauketat et al. 2023.)

Precinct characteristics

Unfortunately, understanding Cahokia’s scale, density, and heterogeneity is hampered by the fact that two of its central-complex precincts—East St Louis and St Louis—have been badly damaged or destroyed by the urban-industrial expansion of the modern cities of East St Louis and St Louis, respectively. The entire St Louis precinct was erased through extensive modifications to the western river bluffs following the Civil War. It had been comprised of twenty-six rectangular and circular platform mounds around a three-plus hectare plaza. The entire precinct may have covered c. 100 ha. At its north end over the entrance to a cavern sat the largest of the St Louis mounds, a rectanguloidal ‘ridge top’ form. At least one other natural sinkhole, adjacent to an apparent circular platform mound, afforded access into the watery, karstic underworld below the site.

The East St Louis precinct was not entirely erased, but it was decapitated, its more than forty-five mounds levelled to the ground. Fortunately, the rest of the precinct remains largely intact below the ruined post-industrial landscape of modern-day East St Louis. In the late 2000s, archaeologists from the Illinois State Archaeological Survey salvaged a palimpsest of some 1,500 pole-and-thatch buildings within an 11 ha excavation area (i.e., less than 5 per cent of the site) at this second-largest precinct of Cahokia. The precinct itself is conservatively estimated to encompass 290 ha (or 2.9 km² ) of the Mississippi floodplain fronting the river, not counting the mounded strip of habitation area that continues to the north-east toward Cahokia proper. There are hints in domestic architecture (dating to AD 1050) and in the presence of foreign-style (but locally made) pottery vessels dating to the eleventh through twelfth centuries that residents included both locals and foreigners, the latter from modern-day Missouri, southern Indiana, and Arkansas if not beyond.

Figure \(\PageIndex{2}\): The three precincts—Cahokia, East St Louis, and St Louis—of the Greater Cahokia (pink), the Mississippi floodplain (light blue), the Mississippi River and other water bodies (dark blue), and the Illinois and Missouri uplands (green). The white rectangle at the center of the Cahokia city marks Monks Mound; note that the North Plaza, the area immediately north of the Monks Mounds, is situated in a meander scar, a depressed land elevation likely a former oxbow lake at the time of Cahokia. (From Pauketat et al. 2023.)

Five kilometres to the east-north-east of East St Louis was the western edge of the Cahokia precinct, marked by several ridge-top mounds and seamlessly connected to East St Louis by the previously noted row of mounds and occupation debris along Indian Lake. Three more kilometres to the east was the great pyramid of the Cahokia precinct, Monks Mound, and the 24 ha ‘Grand Plaza’ that it faced (Fig. \(\PageIndex{3}\)). The Cahokia precinct is estimated to have covered some 1,300 ha (or 13 km²), about 180 ha (or 14 per cent) of which consisted of ‘high-density’ habitation areas. In these high-density areas during the urban Lohmann and Stirling phases stood four to nineteen pole-and-thatch buildings per ha (400–1,900 per km²) at any one time, assuming building longevity estimates of 10–15 years. Gardens and infields may have been scattered across some portions of this area.

The rest of Cahokia’s 1,300 ha area consisted of low-density habitation areas (<4 houses/ha), special pole-and-thatch buildings, mounds (of which there were more than 120), plazas (of which there were several), scattered gardens, borrow-pit reservoirs (depressions left over after construction fills were removed), and marshy backswamp zones. The borrow pits were probably intentionally sited and dug to depths sufficient to hold water and fish for the entire year. Likewise, the large, rectangular ‘North Plaza’, situated in an ancient oxbow channel immediately north of Monks Mound, may have been built expressly to hold water during the wet late winter to early summer months. An even larger naturally marshy lowland at the southern end of the precinct was transected by a kilometre-long earthen causeway, the standing water teeming with amphibians and waterfowl during the late winter, spring, and early summer. Apparently, these natural and built features were not empty meaningless spaces but integral parts of the city. Long causeways ran from the central civic-ceremonial portions of the precinct into the southern wetland, and short causeways ran around borrow pits and between square and circular platform mounds, the latter associated with both water and the water vapour produced inside circular steam baths.

The circular steam bath is one of several kinds of non-domestic architecture that comprise a Cahokian architectonic ‘module’. Besides the circular buildings (large and small), there were oversized square temples or council houses, upright free-standing posts, ‘shrine houses’ or small temples, and T-shaped, L-shaped, and cruciform ‘medicine lodges’. As a set, these buildings defined Cahokia’s precincts, neighbourhoods, and outlying ritual-residential sites down to the level of the ‘nodal farmstead’ — single-family rural domestic habitations that nevertheless featured one or more non-domestic, ostensibly Cahokian structures. Three to five per cent of all structures in the excavated 1,500-structure East St Louis sample, and up to 20 per cent of buildings in Cahokia’s core zone, were comprised of such non-domestic buildings.

From what can be ascertained from many excavated contexts, all such extra-domestic buildings and upright posts might have been occupied, so to speak, by non-human beings. Spirits, for instance, enlivened the ‘medicine bundles’ that would have been kept within some buildings, while ancestral spirits might have animated the wooden posts standing vertically outside such buildings from time to time. That is, these were not merely passive things or places of worship. Rather, they manifested the gods themselves in the social spaces of people. They were portals to other worlds. Accordingly, Alleen Betzenhauser and Timothy Pauketat (2019) likened their presence to the infusion of non-human or ancestral spiritual powers into residential zones. Such an infusion was likely a top-down process, as evidence in a series of oversized rectangular temples built in a grid pattern at East St Louis. In a sense, the non-human beings within human residential sectors made Cahokian urbanity even more heterogeneous than it was based only on the diverse cultural backgrounds of people.

Figure \(\PageIndex{3}\): Monks Mound, the centerpiece of Cahokia's urban monuments, as seen today. Scholars suggest that the North Plaza immediately north of the mound "may have been built expressly to hold water during the wet late winter to early summer months" (Pauketat et al. 2023) and "was an inundated feature on the landscape throughout Cahokia’s occupation" (Rankin, 2022). (Image from NARA)

Vitality, anomaly, and fragility

Beginning at AD 1050, the rate of Cahokian development and the scale of Cahokian construction, resettlement, and ceremonial events was unprecedented, and indicate the willing participation of tens of thousands of locals, immigrants, and pilgrims. People wanted to be a part of Cahokia, and they labored to make it so. Arguably, this energy was a function of Cahokia’s location—in the middle of a special, animate regional landscape characterized by easy access to different kinds of water (subterranean groundwater, river water, backwater, rain water)—and its mode of incorporating other-than-human powers into its urban spaces, including those related to water. That same landscape, carved up by numerous oxbow lakes and marshes and studded by karst sinkholes and caverns to the north, south, and west, might be the reason for the odd distanciated configuration of the central complex. That is, the distribution of the powerfully animate landscape features meant that the seat of regional authority, whatever it was, had to spread out to occupy or assemble those features under one umbrella—Cahokia. Perhaps, given Cahokia’s incorporation of multiple other-than-human forces into the daily domestic spaces of individual precincts via its modular architecture, we may be seeing evidence of a central core insufficiently strong to be materialized as a single nucleated city, despite the obvious magnitude of Monks Mound in the middle of the Cahokia precinct.

Cahokian modular architecture in the countryside as well as the city may attest to the same thing. Indeed, the same episodes of change—transformation, expansion, and contraction—dating to AD 1050, the early 1100s, and c. 1200 characterize the four rural localities reviewed here. Possibly, this is evidence of a high degree of articulation between rural farmers and Cahokians, perhaps through events like those that produced the layers of sub-Mound 51 ceremonial-feasting debris. True, each rural locality reviewed herein seems to reveal a slightly different aspect of this regional articulation, probably a result of rural people exerting their own agency or living their own history to some extent. Also evident, however, is the agency of a Cahokian elite. We see it most clearly in the overbuilt and underused habitation areas at East St Louis (in the so-called Southside and Northside excavations) and at Grossmann. Their physical remains are found in the theatrical mortuaries of the region’s ridge-top mounds.

Presumably, these were the Cahokians who had a hand in directing the urban development of Cahokia. And we might presume that foremost in their minds would have been the production of sufficient foodstuffs, fish, and wild game to supply the necessary support for the farm families who cleared the fields, levelled the precinct and shrine-complex landforms, provisioned the ceremonies and festivals, built the two hundred earthen pyramids, and filled the storehouses of the elites. In addition to their support and encouragement for farmers, it remains possible under the circumstances that elite management of the region’s resources may have been necessary to maintain the Cahokian dynamo. Someone probably had to oversee the rapid construction of housing at and after ad 1050. Someone would have to manage the collection of hundreds to thousands of untold quantities of tree saplings, wattle, and thatch for the roof of these same houses; this would have meant setting aside, and then cutting and hauling, great quantities of poles, wattle, and thatch. Ample supplies of wood would have been available from across the floodplain and uplands. Thatch would have been readily available from the Richland-Complex prairies to the east of the city.

The procurement of game animals, which were clearly taken in large numbers for central events (such as the feasts in Cahokia’s Grand Plaza), may have presented the people of Greater Cahokia with a managerial challenge. Deer, for instance, are easily overhunted and subject to population crashes. Yet unambiguous archaeological signatures exist of higher-quality cuts of deer meat disproportionately consumed at Cahokia. To ensure that adequate deer were always available, game reserves (nearly invisible archaeologically) may have been necessary. Horseshoe Lake would have been ideal. To produce such quantities of meat for the precincts’ events and elites, hunters may have lined up across the southern end of the Horseshoe Lake peninsula to drive the quadrupeds north before them. Or they may have culled the deer populations of the adjacent Ozark Mountains to the south and west of the American Bottom. Somebody likely specialized in the process of borrowing the earth used to build the city’s causeways and platforms. Of course, there was no shortage of earth in and around Cahokia but digging and transporting it must have been organized by people with knowledge of soil properties and the rights to do so. Fills were procured from sources that included black waterlogged muds or sands adjacent to the planned monument and from more distant blufftop sources around the American Bottom. Working with the various kinds of earth would have entailed a basic understanding of their properties when applied as they were in various dry-mixed and wet-plastic states in layers one atop the other.

Finally, someone or some corporate entity was probably responsible for organizing the cutting and hauling of wood. This is especially true of great cypress logs that were probably cut from stands along the Mississippi River in southern Illinois. Such logs were dressed by woodworkers using chert-bladed adzes during central Cahokian festivals, as indicated by thousands of wood chips and bark from sub-Mound 51 deposits. They were then emplaced in large post pits at each Cahokian precinct, sometimes as parts of larger galleries or rows. These galleries, along with the extensive earthmoving operations, the monumental pole-and-thatch building constructions, and the creation of earthen platforms, causeways, and plazas, seem to have been used to create grand theatrical spaces that aligned people and spirits with cosmic cycles via the precinct and shrine-complex grids. Hundreds to thousands of people took part in processions, ceremonies, feasts, and constructions. Cahokians even carried their vision if not their bundles far aeld. Foreign dignitaries likely arrived to learn the secrets of Cahokia’s powerful medicine. The fervour spread.

The impressive scale and vitality of Greater Cahokia aside, there are reasons to suspect that urbanism in an ‘ill-favoured’ patch of floodplain, focused so exclusively on the performative, religious aspects of human experience, would have been uniquely fragile. In fact, recent hydroclimatic investigations have called the long-term sustainability of Cahokia into question, given paleoenvironmental indicators of droughts and one-off floods in the later 1100s and 1200s. That sustainability seems especially at issue given the general absence at and around Cahokia of the kind of urban infrastructure evident in other precontact American contexts.

That is, Cahokia lacked systems or facilities that provisioned food and water or that supplied the transportation, communication, and waste management needs to a public while they reduced the costs of such provisioning or facilitation. Where, for instance, are the water-control and drainage features built for non-religious, non-ceremonial, civic purposes? Possibly, the North Plaza was engineered to retain water that moved through the Cahokia Creek bottom (and the ancient, abandoned Mississippi River channel in which it sits). Likewise, the sandy and topographic properties of the Grand Plaza seem to have enhanced the drainage of surface water; a narrow ditch probably drained surface water from a residential area at Cahokia proper; and borrow-pit reservoirs may have been intended to supply the drinking water needs for the people of the precincts. But all of these are low-level if not incidental systems at best.

Besides these features, no higher-level water-management infrastructure has yet been identified at and around Cahokia. For example, irrigation features are unknown. Perhaps they were deemed unnecessary given the floodplain’s ordinarily high productivity levels. Similarly, there are no identified precolonial-era earthen dams or retention basins in the critical base-of-the-bluff zone east of Cahokia. Yet flash floods that sweep across the American Bottom, originating in the upland Cahokia and Canteen Creek watersheds to the east, were probably as common in the past as they are today.

Perhaps water-control features may yet be discovered buried beneath modern landscape alterations. Or perhaps the absence of such water-control features might be related to the same ontological reverence afforded water by Cahokians as that which lent this early urban experiment its vitality. Elsewhere, Susan Alt (2019) has detailed the multiple watery domains of the Greater Cahokia region, including the floodplain’s many oxbow lakes, the subterranean caverns below the St Louis precinct, the karst landscape north and south of the city, the ‘weeping hill’ atop which the Emerald Acropolis was built, and more. Perhaps the Cahokians lived with water in ways that discouraged developing high-level water-management infrastructure. If so, this might also help explain the lack of wastewater and septic infrastructure in the city precincts. Presumably, abandoned subterranean food-storage pits, designated borrow pits, and nearby infields were used as toilet facilities. The results of the latter washed off into nearby water bodies.

Key Geologic Concepts:

Alluvial channel; stream flow characteristics; erosional and depositional landforms; floodplain.

Supplemental Materials:

Article: Floodplain(opens in new window). In National Geographic.

Article: "Cahokia: A Pre-Columbian American City" by Timothy R. Pauketat. History Now 28 (Summer 2011).

Article: "Building Monks Mound, Cahokia, Illinois, A.D. 800–1400" by T. Schilling. Journal of Field Archaeology 37, 302 (2012).

Article: "The exceptional environmental setting of the North Plaza, Cahokia Mounds, Illinois, USA" by C.G. Rankin. World Archaeology 54, 84 (2022).