Editing Cahokia (section)

==History==
{{See also|Cahokia polity}}

=== Historical overview ===
Although some evidence exists of occupation during the [[Late Archaic period]] (around 1200 BCE) in and around the site,<ref>James M. Collins, [https://archive.org/details/archaeologyofcah00coll ''The archaeology of the Cahokia Mounds ICT-II''], Springfield IL: Illinois Historic Preservation Agency (1990) {{ISBN|0-942579-10-0}}</ref> 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.<ref>Emerson and Barry, ''Cahokia and the Hinterlands'', 33 & 46</ref> The inhabitants left no written records beyond symbols on pottery, marine shell, copper, wood, and [[Mississippian stone statuary|stone]], but the evidence of elaborately planned community, woodhenge, mounds, and burials later in time reveal a complex and sophisticated society.<ref>Townsend, Sharp, and Bailey {{page needed|date=December 2013}}</ref>

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 United States|Eastern]], and Southeastern United States. Cahokia was located in a strategic position near the confluence of the [[Mississippi River|Mississippi]], [[Missouri River|Missouri]], and [[Illinois River|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]],<ref name="ILLINOISAGRI">{{cite web |title=Illinois Agriculture-Technology-Hand tools-Native American Tools |url=http://www.museum.state.il.us/exhibits/agriculture/htmls/technology/hand_tools/tech_hand_na.html |access-date=July 12, 2010}}</ref> shark teeth,<ref>{{Cite book |last=Kozuch |first=Laura |title=Zooarchaeology Beyond Human Subsistence |date=2025 |publisher=University of Utah Press |editor-last=Wong |editor-first=Gillian |location=Salt Lake City, UT |chapter=Shark Tooth Artifacts at Cahokia}}</ref> and [[Sinistrofulgur perversum|lightning whelk]] shells.<ref>{{Cite journal |last=Kozuch |first=Laura |date=2022 |title=Shell Bead Crafting at Greater Cahokia |url=https://doi.org/10.1177/01976931211048205 |journal=North American Archaeologist |volume=43 |issue=1 |pages=64–94}}</ref>
{| class="wikitable"
|+
!Table<ref name=":7" /><ref name=":13" />
!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 Complex|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.
|}

===Development (9th and 10th centuries)===
[[File:Mississippian cultures HRoe 2010.jpg|thumb|upright=1.5|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.]]
[[File:Pauketat GreaterCahokia CahokiaasUrbanAnomaly.png|thumb|350x350px|Map of Greater Cahokia in the American Bottom by Dr. Timothy Pauketat. ("TLW" designates Terminal Late Woodland)<ref name=":13">{{Cite journal |last=Pauketat |first=Timothy R. |last2=Alt |first2=Susan M. |last3=Betzenhauser |first3=Alleen M. |last4=Krutchen |first4=Jeffery D. |last5=Benson |first5=Erin M. |date=2023 |title=Cahokia as Urban Anomaly |journal=Journal of Urban Archaeology |volume=7 |pages=253–274}}</ref>]]
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.<ref name=":7">{{Cite journal |last=Stauffer |first=Grant J. |last2=Grooms |first2=Seth B. |last3=Hu |first3=Lorraine W. |last4=Mersmann |first4=Joy |last5=Kidder |first5=Tristram R. |last6=Henry |first6=Edward R. |date=2023 |title=Reimagining the Development of Downtown Cahokia Using Remote Sensing Visualizations from the Western Edge of the Grand Plaza |journal=Land |volume=12 |issue=342}}</ref> 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 {{Convert|35|–|70|ha}} in Cahokia proper, with its beginnings at the end in the late 900s CE.<ref>{{Cite book |last=Kelly |first=John E. |title=Cahokia in Context: Hegemony and Diaspora |last2=Brown |first2=James A. |date=2020 |publisher=University of Florida Press |pages=11–31 |chapter=In the Beginning: Contextualizing Cahokia’s Emergence}}</ref> 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.<ref name=":6">{{Cite book |last=Betzenhauser |first=Alleen |title=Mississippian Beginnings |date=2017 |publisher=University of Florida Press |pages=71–96 |chapter=Cahokia’s Beginnings: Mobility, Urbanization, and the Cahokian Political Landscape}}</ref> 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.<ref name=":8">{{Cite book |last=Fritz |first=Gayle |title=Feeding Cahokia: Early Agriculture in the North American Heartland |date=2019 |publisher=University of Alabama Press}}</ref>

===Rise and peak (11th and 12th centuries)===
In the years around 1050 CE, Cahokia experienced a “Big Bang.” The city-proper's three urban precincts: St. Louis, East St. Louis, and Cahokia were  all constructed at this time.<ref>{{Cite journal |last=Pauketat |first=Timothy |last2=Alt |first2=Susan |last3=Betzenhauser |first3=Alleen M. |last4=Krutchen |first4=Jeffery D. |last5=Benson |first5=Erin M. |date=2023 |title=Cahokia as Urban Anomaly |journal=Journal of Urban Archaeology |volume=7 |pages=253–274}}</ref> 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.<ref name=":6" /> 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 {{convert|55|e6ft3|e6m3|abbr=off|sp=us}} 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.<ref>{{Cite news |last=Bey |first=Lee |url=https://www.theguardian.com/cities/2016/aug/17/lost-cities-8-mystery-ahokia-illinois-mississippians-native-americans-vanish |title=Lost cities #8: mystery of Cahokia – why did North America's largest city vanish? |date=August 17, 2016 |work=The Guardian |access-date=March 30, 2020 |language=en-GB |issn=0261-3077}}</ref>

At the high point of its development, Cahokia was the largest urban center north of the great [[Mesoamerica]]n 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",<ref>Benson LV, Berry MS, Jolie EA, Spangler JD, Stahle DW, Hattori EM. "Possible impacts of early-11th-, middle-12th-, and late-13th-century droughts on western Native Americans and the Mississippian Cahokians." ''Quaternary Science Reviews'' 2007, 26:336–350,</ref> an estimate that applies only to a {{convert|1.8|km2|adj=on}} high-density central occupation area.<ref name=":5">{{cite journal | last1 = Benson | first1 = L. V. | last2 = Pauketat | first2 = T. R. | last3 = Cook | first3 = E. R. | year = 2009 | title = Cahokia's Boom and Bust in the Context of Climate Change | url = http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1733&context=usgsstaffpub| journal = American Antiquity | volume = 74 | issue = 3| pages = 467–483 | doi = 10.1017/S000273160004871X | s2cid = 160679096 | url-access = subscription }}</ref> 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.<ref name=":1">Glenn Hodges, "[https://web.archive.org/web/20180824183243/https://www.nationalgeographic.com/magazine/2011/01/americas-forgotten-city/ America's Forgotten City]", ''[[National Geographic]]'', January 2011.</ref> Archaeologists estimate the city's population at between 6,000 and 40,000 at its peak.<ref name=":1" /> If the highest population estimates are correct, Cahokia was larger than any subsequent city in the United States until the 1780s, when [[Philadelphia|Philadelphia's]] population grew beyond 40,000.<ref>United States Census Office, ''A Century of Population Growth from the First Census of the United States to the Twelfth: 1790–1900'', Government Printing Office, 1909, p. 11</ref> Its population may have been larger than contemporaneous [[London]]<ref>{{Cite news |last=Wills |first=Matthew |date=August 15, 2017 |title=The Mysterious Pre-Columbian Settlement of Cahokia |url=https://daily.jstor.org/the-mysterious-pre-columbian-settlement-of-cahokia/ |access-date=June 19, 2022 |language=en-US}}</ref> and [[Paris]].<ref>{{Cite news |last=Smith |first=Jen Rose |title=The US' lost, ancient megacity |url=https://www.bbc.com/travel/article/20210412-the-us-lost-ancient-megacity |access-date=June 19, 2022 |language=en}}</ref>

Studies of Cahokia's rise see large-scale immigration as an essential contributor to the city's initial rapid growth.<ref name=":2">{{Citation |last=Emerson |first=Thomas E. |title=The dangers of diversity: The consolidation and dissolution of Cahokia, native North America's first urban polity |date=2015 |work=Beyond Collapse: Archaeological Perspectives on Resilience, Revitalization, and Transformation in Complex Societies |pages=147–178 |url=https://experts.illinois.edu/en/publications/the-dangers-of-diversity-the-consolidation-and-dissolution-of-cah |access-date=June 3, 2024 |series=Center for Archaeological Investigations Occasional Paper |publisher=SIU Press |isbn=978-0-8093-3400-1 |last2=Hedman |first2=Kristin M.}}</ref> 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 site|Yankeetown]]), Lower Mississippi Valley ([[Coles Creek culture|Coles Creek]]), Upper Midwest (below), and south-central plains ([[Caddoan Mississippian culture|Caddo]]).<ref name=":6" /> Many of these immigrants moved into outlying villages in the eastern uplands, referred to as the Richland Complex. Intensive farming<ref name=":9">{{Cite journal |last=Pauketat |first=Timothy |date=2003 |title=Resettled Farmers and the Making of a Mississippian Polity |journal=American Antiquity |volume=68 |issue=1 |pages=39–66}}</ref> and textile production<ref>{{Cite journal |last=Alt |first=Susan |date=1999 |title=Spindle Whorls and Fiber Production at Early Cahokian Settlements |journal=Southeastern Archaeology |volume=18 |issue=2 |pages=124–134}}</ref> 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.<ref>{{Cite book |last=Alt |first=Susan |title=Leadership and Polity in Mississippian Society |date=2006 |publisher=Center for Archaeological Investigations |location=Carbondale, Illinois |pages=289–308 |chapter=The Power of Diversity: The Roles of Migration and Hybridity in Culture Change}}</ref> One such example, the common mound-and-plaza pairing, was adopted from longstanding [[Coles Creek culture|Coles Creek]] organizational principles.<ref>{{Cite book |last=Steponaitis |first=Vincas |title=Medieval Mississippians: The Cahokian World |last2=Kassabaum |first2=Megan C. |last3=O'Hear |first3=John W. |date=2015 |publisher=School for Advanced Research |location=Santa Fe, New Mexico |pages=13–19 |chapter=Cahokia's Coles Creek Predecessors}}</ref>

Contacts across the mid-continent and possibly beyond are attested to have reached a peak between 1050 and 1150 CE. Mill Creek chert from [[Alexander County, Illinois|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.<ref>{{Cite book |last=Cobb |first=Charles |title=From Quarry to Cornfield: The Political Economy of Mississippian Hoe Production |date=2000 |publisher=The University of Alabama Press}}</ref><ref name="SNOW2010" /> [[Mississippian culture pottery]] and stone tools in the Cahokian style were found at the Silvernale site<ref>[https://cannonvalleytrail.com/cultural/ Cannon Valley Trail]</ref> near [[Red Wing, Minnesota]], and materials and trade goods from Pennsylvania, the Gulf Coast, and Lake Superior have been excavated at Cahokia.<ref>{{cite web|url=https://www.washingtonpost.com/wp-srv/national/daily/march/12/cahokia.htm |title=Ancient Cahokia |work=WashingtonPost.com |date=March 12, 1997 |access-date=December 16, 2021}}</ref> Cahokians traveled down to the [[Carson Mounds|Carson site]] in [[Coahoma County, Mississippi]] and built a settlement during the 12th century.<ref>{{Cite book |last=Johnson |first=Jay K. |title=Cahokia in Context: Hegemony and Diaspora |last2=Connaway |first2=John M. |date=2020 |publisher=University Press of Florida |chapter=Carson and Cahokia}}</ref> Others paddled upriver to the site of Trempleau Bluffs in [[Trempealeau County, Wisconsin|southern Wisconsin]], to create a mounded religious center at the end of the 11th century.<ref>{{Cite journal |last=Pauketat |first=Timothy |last2=Boszhardt |first2=Robert F. |last3=Kolb |first3=Michael |date=2017 |title=Trempealeau’s Little Bluff: An Early Cahokian Terraformed Landmark in the Upper Mississippi Valley |journal=Midcontinental Journal of Archaeology |volume=42 |issue=2 |pages=168–199}}</ref>
[[File:Mound 72 sacrifice ceremony HRoe 2013.jpg|thumb|upright=0.9|A [[human sacrifice]] of fifty-three women at Cahokia]]
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.<ref>{{Cite book |last=Alt |first=Susan |title=Cahokia in Context: Diaspora and Hegemony |date=2020 |publisher=University Press of Florida |pages=32–48 |chapter=The Implications of the Religious Foundations at Cahokia}}</ref> 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 [[Moonrise and moonset|lunar events]] in its 18.6 year cycle.<ref>{{Cite book |last=Alt |first=Susan |title=Religion and Politics in the Ancient Americas |last2=Pauketat |first2=Timothy |date=2017 |pages=51–75 |chapter=The Elements of Cahokian Shrine Complexes and the Basis of Mississippian Religion}}</ref> 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 [[Sweat lodge|sweatlodges]].<ref>{{Cite book |last=Emerson |first=Thomas E. |title=Cahokia and the Architecture of Power |publisher=The University of Alabama Press |year=1997}}</ref> Distinctive rituals have archaeologically documented at these complexes involving tobacco, red cedar, agricultural produce, and female [[Mississippian stone statuary|Cahokian flint clay figurines]].<ref>{{Cite book |last=Emerson |first=Thomas E. |title=Medieval Mississippians: The Cahokian World |date=2015 |pages=54–62 |chapter=The Earth Goddess Cult at Cahokia}}</ref> 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.<ref>{{Cite book |last=Baires |first=Sarah |title=Land of Water, City of the Dead: Religion and Cahokia's Emergence |date=2014 |publisher=The University of Alabama Press}}</ref>

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.<ref name=":5" /> 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.<ref name="SNOW2010" />

===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.<ref name=":10">{{Cite journal |last=Pauketat |first=Timothy |last2=Fortier |first2=Andrew C. |last3=Alt |first3=Susan |last4=Emerson |first4=Thomas E. |date=2013 |title=A Mississippian Conflagration at East St. Louis and Its Political-Historical Implications |journal=Journal of Field Archaeology |volume=38 |issue=3 |pages=210–226}}</ref> 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.<ref name=":7" /> People began leaving the city in larger numbers beginning in the late 12th century.<ref name=":11">{{Cite book |last=McNutt |first=Charles H. |title=Cahokia in Context: Hegemony and Diaspora |date=2020 |publisher=University Press of Florida |pages=409–411 |chapter=Conclusion}}</ref> 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.<ref>{{Cite journal|last=Buchanan|first=Meghan E.|date=November 9, 2019|title=Diasporic Longings? Cahokia, Common Field, and Nostalgic Orientations|url=http://dx.doi.org/10.1007/s10816-019-09431-z|journal=Journal of Archaeological Method and Theory|volume=27|issue=1|pages=72–89|doi=10.1007/s10816-019-09431-z|s2cid=210477600|issn=1072-5369|url-access=subscription}}</ref><ref name="reader">Henderson, Harold. "[http://www.chicagoreader.com/chicago/the-rise-and-fall-of-the-mound-people/Content?oid=902673 The Rise and Fall of the Mound People]". ''Chicago Reader''. June 29, 2000. Retrieved 2016-05-28.</ref>[[File:Mississippian culture mound components HRoe 2011.jpg|thumb|upright=1.4|alt=A mound diagram of the Mississippian culture|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]]
Scholars have proposed environmental factors, such as [[environmental degradation]] through overhunting, deforestation<ref>{{Cite journal|last=Woods|first=William I.|date=June 1, 2004|title=Population nucleation, intensive agriculture, and environmental degradation: The Cahokia example|url=https://doi.org/10.1023/B:AHUM.0000029398.01906.5e|journal=Agriculture and Human Values|language=en|volume=21|issue=2|pages=255–261|doi=10.1023/B:AHUM.0000029398.01906.5e|s2cid=153665089|issn=1572-8366|url-access=subscription}}</ref> and pollution,<ref>{{Cite journal|last1=Pompeani|first1=David P.|last2=Hillman|first2=Aubrey L.|last3=Finkenbinder|first3=Matthew S.|last4=Bain|first4=Daniel J.|last5=Correa-Metrio|first5=Alexander|last6=Pompeani|first6=Katherine M.|last7=Abbott|first7=Mark B.|date=December 27, 2018|title=The environmental impact of a pre-Columbian city based on geochemical insights from lake sediment cores recovered near Cahokia|url=http://dx.doi.org/10.1017/qua.2018.141|journal=Quaternary Research|volume=91|issue=2|pages=714–728|doi=10.1017/qua.2018.141|s2cid=133966204|issn=0033-5894|url-access=subscription}}</ref> and climatic changes, such as increased flooding<ref>{{cite web|date=May 4, 2015|title=New insights into the curious disappearance of the Cahokia Mounds builders|url=https://news.stlpublicradio.org/health-science-environment/2015-05-04/new-insights-into-the-curious-disappearance-of-the-cahokia-mounds-builders|access-date=November 7, 2020|website=St. Louis Public Radio|language=en}}</ref> and droughts,<ref>{{Cite journal|last1=Benson|first1=Larry V.|last2=Pauketat|first2=Timothy R.|last3=Cook|first3=Edward R.|date=2009|title=Cahokia's Boom and Bust in the Context of Climate Change|url=https://www.jstor.org/stable/20622439|journal=American Antiquity|volume=74|issue=3|pages=467–483|doi=10.1017/S000273160004871X|jstor=20622439|s2cid=160679096|issn=0002-7316|url-access=subscription}}</ref><ref name=":0">{{Cite journal|last1=White|first1=A. J.|last2=Stevens|first2=Lora R.|last3=Lorenzi|first3=Varenka|last4=Munoz|first4=Samuel E.|last5=Schroeder|first5=Sissel|last6=Cao|first6=Angelica|last7=Bogdanovich|first7=Taylor|date=March 19, 2019|title=Fecal stanols show simultaneous flooding and seasonal precipitation change correlate with Cahokia's population decline|journal=Proceedings of the National Academy of Sciences|language=en|volume=116|issue=12|pages=5461–5466|doi=10.1073/pnas.1809400116|issn=0027-8424|pmid=30804191|pmc=6431169|bibcode=2019PNAS..116.5461W |doi-access=free}}</ref> 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.<ref name="Rankin">{{cite journal |last1=Rankin |first1=Caitlin |title=Evaluating narratives of ecocide with the stratigraphic record at Cahokia Mounds State Historic Site, Illinois, USA |journal=Geoarcheology |date=February 12, 2021 |volume=36 |issue=3 |pages=369–387 |doi=10.1002/gea.21848 |bibcode=2021Gearc..36..369R |s2cid=236450497 |url=https://onlinelibrary.wiley.com/doi/10.1002/gea.21848|url-access=subscription }}</ref><ref>{{cite news |last1=Elbein |first1=Asher |title=What Doomed a Sprawling City Near St. Louis 1,000 Years Ago? |url=https://www.nytimes.com/2021/04/24/science/cahokia-mounds-floods.html?action=click&algo=bandit-all-surfaces-engagement-time-weight&block=editors_picks_recirc&fellback=false&imp_id=919268414&impression_id=8b7d43c0-ac22-11eb-8def-498ba9b41c78&index=1&pgtype=Article&pool=editors-picks-ls&region=ccolumn&req_id=608917974&surface=home-featured&variant=5_bandit-all-surfaces-engagement-time-weight&action=click&module=editorContent&pgtype=Article&region=CompanionColumn&contentCollection=Trending |work=[[The New York Times]] |date=April 24, 2021}}</ref><ref name="reader" />

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.<ref>Baltus, Melissa R. 2014. “Transforming Material Relationships: 13th Century Revitalization of Cahokian Religious-Politics.” University of Illinois at Urbana-Champaign.</ref> 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.<ref>Skousen, B. Jacob, and Allison L. Huber. 2018. “The Moorehead Phase Occupation at the Emerald Acropolis.” ''Midcontinental Journal of Archaeology'' 43 (3): 214–256.</ref> Altogether, this has been taken as a time when centralized political structures were weakening and essential religious practices were rethought.<ref name=":10" />

Political, economic, or cultural problems may also have contributed to the community's decline.<ref>{{Cite book |last=Milner |first=George |title=The Cahokia chiefdom: the archaeology of a Mississippian society |publisher=Smithsonian Inst Press |year=1998}}</ref> 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.<ref name=":2" /> It is likely that social and environmental factors combined to produce the conditions that led people to leave Cahokia.<ref>{{Cite book |last=Kelly |first=John |title=Contemplating Cahokia's collapse. In: Global Perspectives on the Collapse of Complex Systems |publisher=Maxwell Museum of Anthropology |year=2009 |pages=147–168}}</ref><ref name=":0" />

Cahokia's connections to the surrounding regions seems to have shifted from one of direct contact and outpost construction to one of dispersal. The immigrant populations inhabiting upland villages in the so-called Richland Complex were some of the first to leave the city.<ref name=":9" /> Many people leaving Cahokia went south into the [[Cairo, Illinois|Cairo Lowlands]] of southern Illinois and further south in the Central Mississippi Valley. Later, some left for [[Cumberland River|The Cumberland Basin]] in central Tennessee.<ref>Sullivan, Lynne P., Kevin E. Smith, Scott Meeks, and Shawn M. Patch. 2024. “Tracking Mississippian Migrations from the Central Mississippi Valley to the Ridge and Valley with a Unified Absolute Chronology.” ''American Antiquity'' 89 (2): 1–17.</ref> Finely crafted artifacts from Cahokia, such as [[Mississippian copper plates|copper repoussé plates]] and engraved shell, appear at powerful centers such as [[Moundville Archaeological Site|Moundville]] and [[Etowah Indian Mounds|Etowah]] only after 1250 CE.<ref>Cobb, Charles R., and Adam King. 2015. “The Rise and Demise of Mississippian Capitals in the Southeast.” In ''Medieval Mississippians: The Cahokian World''. Santa Fe, New Mexico: School for Advanced Research Press.</ref>
[[File:Cahokia Mounds -- UNESCO reconstruction.jpg|thumb|Illustration of Cahokia as it may have looked at its peak 1050–1350 AD]]
Another possible cause is invasion by outside peoples. Many theories since the late 20th century propose conquest-induced political collapse as the primary reason for Cahokia's abandonment.<ref>Emerson 1997, [[Timothy Pauketat|Pauketat]] 1994.</ref> Evidence of warfare found is defensive wooden stockade and watchtowers that enclosed Cahokia's main ceremonial precinct. Multiple associated 13th century burned villages in the [[Illinois River|Illinois River Valley]] to the north speak to the rising tensions at the time.<ref>Wilson, Gregory D. 2015. “Incinerated Villages in the North.” In ''Medieval Mississippians: The Cahokian World'', 99–104. Santa Fe, New Mexico: School for Advanced Research Press.</ref> Palisades become popular across parts of the Midwest and mid-South during the 13th century as communities begin living together in much more nucleated settlement types.<ref name=":11" /> However, Cahokia's [[palisade]] may have been more for ritual or formal separation than for military purposes, but bastioned palisades almost always indicate warfare.<ref>{{Cite journal |last=Keeley |first=Lawrence H. |last2=Fontana |first2=Marisa |last3=Quick |first3=Russell |date=March 1, 2007 |title=Baffles and Bastions: The Universal Features of Fortifications |url=https://doi.org/10.1007/s10814-006-9009-0 |journal=Journal of Archaeological Research |language=en |volume=15 |issue=1 |pages=55–95 |doi=10.1007/s10814-006-9009-0 |issn=1573-7756|url-access=subscription }}</ref> As Cahokia's population shrank over the 13th century, Cahokia's palisade was rebuilt several times to encompass increasingly-smaller portions of the city.<ref>{{Cite journal |last=Shackelford |first=Alan G. |date=2007 |title=The Frontier in Pre-Columbian Illinois |url=https://www.jstor.org/stable/40204685 |journal=Journal of the Illinois State Historical Society |volume=100 |issue=3 |pages=182–206 |issn=1522-1067}}</ref>

Diseases transmitted among the large, dense urban population are another possible cause of decline. Similarly, health issues like [[pellagra]] are known to arise through maize-intense diets like Cahokia's.<ref>{{Cite journal |last=Brenton |first=Barrett P. |last2=Paine |first2=Robert R. |date=September 18, 2007 |title=Reevaluating the Health and Nutritional Status of Maize-Dependent Populations: Evidence for the Impact of Pellagra on Human Skeletons from South Africa |url=http://www.tandfonline.com/doi/abs/10.1080/03670240701486545 |journal=Ecology of Food and Nutrition |language=en |volume=46 |issue=5-6 |pages=345–360 |doi=10.1080/03670240701486545 |issn=0367-0244|url-access=subscription }}</ref> However, evidence tying nutritional deficiencies to a broader societal collapse has not been conclusively identified.<ref name=":2" /><ref name=":4">{{Cite book |last=Mailer |first=Gideon A. |url=https://www.jstor.org/stable/j.ctt2204p9g |title=Decolonizing the Diet: Nutrition, Immunity, and the Warning from Early America |last2=Hale |first2=Nicola E. |date=2018 |publisher=Anthem Press |isbn=978-1-78308-714-3}}</ref> At Cahokia's beginning around CE 1050, [[hominy]] was made though [[nixtamalization]] that made the maize more nutritious.<ref>{{Cite book |last=Simon |first=Mary L. |title=East St. Louis Precinct Faunal and Botanical Remains |last2=Kuehn |first2=Steven R. |date=2023 |publisher=Illinois State Archaeological Survey |editor-last=Skousen |editor-first=B. Jacob |location=Champaign, IL |pages=303–392 |chapter=Summary and Implications}}</ref> Recent research indicates that early Cahokians nixtamalized maize but then stopped nixtamalizing maize around CE 1200.<ref name="Kozuch 2023 104277">{{Cite journal |last=Kozuch |first=Laura |date=2023 |title=Cahokia's shell bead crafters and maize producers: A re-examination of the data |url=https://doi.org/10.1016/j.jasrep.2023.104277 |journal=Journal of Archaeological Science: Reports |volume=52 |pages=104277 |doi=10.1016/j.jasrep.2023.104277 |issn=2352-409X|url-access=subscription }}</ref> Intense reliance on maize that is not nixtamalized may result in [[pellagra]] and death.<ref>{{Cite journal |last=Rajakumar |first=K. |date=2000 |title=Pellagra in the United States: a historical perspective |url=https://pubmed.ncbi.nlm.nih.gov/10728513/ |journal=Southern Medical Journal |volume=93 |issue=3 |pages=272–277 |issn=0038-4348 |pmid=10728513}}</ref> Isotope analysis of burial remains at Cahokia has revealed iron-deficiency anemia and tooth enamel defects potentially stemming from Cahokia's reliance on maize.<ref>{{Cite book |last=Emerson |first=Thomas E. |title=Beyond Collapse: Archaeological Perspectives on Resilience, Revitalization, and Transformation in Complex Societies |last2=Hedman |first2=Kristin M. |date=2016 |publisher=Center for Archaeological Investigations |series=Occasional Paper No. 42 |location=Carbondale, IL |pages=147–175}}</ref>

Together with these factors, researchers found evidence in 2015 of major floods at Cahokia, so severe as to flood dwelling places. Analysis of sediment from beneath [[Horseshoe Lake (Madison County, Illinois)|Horseshoe Lake]] has revealed that two major floods occurred in the period of settlement at Cahokia, in roughly 1100–1260 and 1340–1460.<ref name="insight">[http://news.stlpublicradio.org/post/new-insights-curious-disappearance-cahokia-mounds-builders Durrie Bouscaren, "New insights into the curious disappearance of the Cahokia Mounds builders"], St. Louis Public Radio, May 4, 2015, accessed May 6, 2015</ref><ref>[http://popular-archaeology.com/issue/spring-2015/article/cahokia-s-rise-and-fall-linked-to-river-flooding "Cahokia's rise and fall linked to river flooding"], ''Popular Archaeology'', Spring 2015</ref>  While flooding may have occurred early in the rise of the city, it seems not to have deterred the city builders; to the contrary, it appears they took steps such as creating channels, dikes, and [[levee]]s that protected at least the central city throughout its inhabited history.<ref name="Rankin" /> In another indication of flood mitigation efforts, Cahokians dispersed their agricultural lands among both lowland and upland fields, thereby reducing the chances that a single cataclysmic flood would wipe out the city's food supply.<ref name=":2" />

=== Abandonment and resettling (15th through 19th centuries) ===
Cahokia's abandonment came in tandem with the abandonment of the wider surrounding region, referred to by scholars as "the Vacant Quarter." Populations left what is now southern Illinois; the [[Lower Ohio River|Lower Ohio Drainage]] in southern Indiana; nearly the entirety of western Kentucky and Tennessee;  most of southeastern Missouri excepting the [[Missouri Bootheel|Bootheel]]; and the Upper [[Tombigbee River|Tombigbee drainage]] in northeastern Mississippi.<ref>Cobb, Charles R., Anthony M. Krus, Aaron Deter-Wolf, Kevin E. Smith, Edmond A. Boudreaux III, and Brad R. Lieb. 2023. “The Beginning of the End: Abandonment Micro‐histories in the Mississippian Vacant Quarter.” ''Journal of Archaeological Method and Theory'' 31:619–43.</ref><ref>{{Cite web |title=Exploring the Vacant Quarter |url=https://www.floridamuseum.ufl.edu/histarch/research/mississippi/exploring-the-vacant-quarter/ |access-date=November 23, 2024 |website=Historical Archaeology |language=en-US}}</ref> The region may have been used by occasional hunting parties but there was no settlement of any substantial kind at Cahokia, nor in the wider region, from 1400 to 1600 CE. However archeologists discovered evidence in 2020 that there was a population rebound in the greater area following Cahokia's population minimum in 1400, with the population reaching a population maximum in 1650 and then declining again in 1700.<ref>{{cite journal |last1=White |first1=A.J. |last2=Munoz |first2=Samuel E. |last3=Schroeder |first3=Sissel |last4=Stevens |first4=Lora R. |title=After Cahokia: Indigenous Repopulation and Depopulation of the Horseshoe Lake Watershed AD 1400–1900 |journal=American Antiquity |date=January 2020 |volume=85 |issue=2 |pages=263–278 |doi=10.1017/aaq.2019.103 |doi-access=free }}</ref>

[[Dhegihan migration|Dhegiha Siouan migration]] was in part responsible for the depopulation of Cahokia. The city is the heritage of many contemporary [[Native Americans in the United States|Native American]] communities, the former group in particular. [[Ponca]] oral tradition specifies their ancestor's time in Cahokia, calling the city or its location "P'ahe zide" [red hill].<ref>Headman, Louis V. 2020. ''Walks on the Ground: A Tribal History of the Ponca Nation''. Lincoln: University of Nebraska Press.</ref> Following the city's abandonment as such, [[Algonquian peoples|Algonquian]] groups from the east moved into the Vacant Quarter in the mid-17th century, specifically those of the [[Illinois Confederation]].<ref>{{Cite book |last=Cook |first=Robert A. |title=The Historical Turn in Southeastern Archaeology |date=2020 |pages=82–100 |chapter=Becoming and Descending: Examining the Historical-Processual Continuum in American Archaeology along a Mississippian Periphery}}</ref> The [[Cahokia people|Cahokia tribe]] was one such group and from whom the site gets its name.

While Cahokia proper had ceased to exist, the mounds continued to be present on the landscape. Various French settler-colonial families are documented to have claimed the land of the city during the 18th century. [[St. Louis]] was defined by the mounds that Cahokians had constructed across the river, referred to at one point as "Mound City."<ref name=":12">{{Cite book |last=Cleary |first=Patricia |title=Mound City: The Place of the Indigenous Past and Present in St. Louis |date=2024 |publisher=University of Missouri Press}}</ref> Nearly all these mounds in Downtown St. Louis were destroyed and used for fill in the growing city's construction in the mid-19th century.<ref>{{Cite web |date=June 25, 2012 |title=The Big Mound of St. Louis |url=https://www.distilledhistory.com/bigmound/ |access-date=November 23, 2024 |website=Distilled History |language=en-US}}</ref> As Native Americans were forcibly removed from the land through treaties and war (particularly the [[Black Hawk War (1865–1872)|Black Hawk's War]]), their claim to the land and its usage was usurped.<ref name=":12" /> In downtown Cahokia a group of early 19th century (circa 1809) [[Trappists|Trappist Monks]] lived on the grounds. Later the land was farmed by the Ramey family through the latter-half of the 19th century. This is when serious archaeological interest began as Euro-American settlers began trying to make sense of the site.<ref>{{Cite book |last=Fowler |first=Melvin |title=The Cahokia Atlas: A Historical Atlas of Cahokia Archaeology |date=1989 |publisher=Illinois Historic Preservation Society}}</ref>