Editing Cahokia (section)

===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" />