In a recent article, A.J. White, Samuel E. Munoz, Sissel Schroeder, and Lora R. Stevens (Reference White, Munoz, Schroeder and Stevens2020) contend that after Cahokia's decline in AD 1400, the native population of the Horseshoe Lake Watershed (located in the American Bottom region) rebounded beginning in AD 1500, reached a population maximum at 1650, and declined again around 1700. They also suggest that the native groups who repopulated the area in 1500 were part of the Illinois Confederation. These arguments hinge on a human population reconstruction (based on fecal stanol concentrations recovered in two sediment cores from Horseshoe Lake) coupled with existing historical, archaeological, and environmental data. We appreciate the authors’ efforts to understand this crucial period in the American Bottom region. Their arguments, however, are questionable because they discount regional archaeological and historical data, and they do not consider alternative hypotheses that might explain the elevated fecal stanol concentrations.

White and colleagues’ attempt to reconcile elevated stanol concentrations with regional archaeological and historical data does not accurately represent what is known from these data. The information in the following two paragraphs is based on these data. (Because sources are abundant and space is limited, additional references are provided in Supplemental Text 1.)

First, White and colleagues argue that “archaeologists have poor control over the kinds of artifacts that may have been distinctive to late precontact sites” (Reference White, Munoz, Schroeder and Stevens2020:267) in the American Bottom region. This is incorrect. There is a substantial body of literature on late prehistoric, protohistoric, and early historic sites and material culture in the American Bottom region. Second, they claim that “many native groups were highly mobile at this time” (White et al. Reference White, Munoz, Schroeder and Stevens2020:267), implying that temporary sites are hard to identify archaeologically. In fact, regional archaeologists have identified sites created by small, mobile groups from other time periods, largely because the American Bottom region is one of the most studied and best understood regions in North America due to extensive transportation-based CRM projects. Currently, over 5,800 sites have been recorded, and more than 480 km² have been surveyed in the three counties that comprise the American Bottom region. Additionally, hundreds of sites in the region have been partially or fully excavated. It is also worth noting that the Illinois settlement system consisted of large villages with hundreds or thousands of residents as well as associated seasonal camps. Consequently, if there was a substantial Illinois population in the American Bottom region beginning around 1500, then large pre-1700 Illinois villages would exist in the area, not just temporary camps. Third, White and colleagues (Reference White, Munoz, Schroeder and Stevens2020:268) contend that “historic-era Illinois hunting camps rarely contain diagnostic materials.” This is sometimes true, although a substantial number of hunting camps would have to exist within the Horseshoe Lake watershed to account for an increase in population at this time. If present, then surely some of these camps would yield diagnostic materials (e.g., Danner ware, European metals and beads) that archaeologists would have identified. Fourth, the authors claim that “the research emphasis on Mississippian archaeology may create a recording bias that impacts the identification of Illinois material culture during archaeological survey” (Reference White, Munoz, Schroeder and Stevens2020:268). The majority of the recorded archaeological sites, however, do not date to the Mississippian period, and plenty of research has been done on other time periods in the region based on abundant survey and excavation data. In sum, if a substantial number of late prehistoric–protohistoric sites were present in the Horseshoe Lake Watershed as White and colleagues suggest, then more of these sites would have already been identified.

The authors’ claim that the native peoples who repopulated the region around 1500 were part of the Illinois Confederacy is doubtful. This assumption is based on a direct historical approach: because the Illinois lived in the American Bottom region in the 1700s, “it is likely that a population similar to the Cahokia subgroup occupied the Cahokia region at some point between the depopulation of Cahokia and the historic period” (White et al. Reference White, Munoz, Schroeder and Stevens2020:268). This approach is problematic, however, because there is no indication in historic documents that the Illinois were in the American Bottom region before about 1700, and ceramic complexes associated with pre-1700 Illinois groups (particularly Danner ware) have not been found in the area. Additionally, ceramic evidence suggests that the Illinois came from farther east (the modern state of Ohio) and did not migrate into the modern state of Illinois, specifically the Chicago area, until about 1600. Consequently, the Illinois could not have been in the American Bottom region by 1500 as White and colleagues claim. Moreover, the authors’ equation of the few post-1400 Oneota groups (Siouian speakers) in the American Bottom region with the Illinois (Algonkian speakers) contrasts with views of the potential descendant populations of the Oneota. White and colleagues further argue that their interpretation is valid because regional environmental conditions were favorable for bison hunting and maize horticulture, and historic documents reveal that the Illinois participated in both activities. This argument is questionable because other late prehistoric–protohistoric native groups that passed through the American Bottom region (not just the Illinois) also hunted bison and grew maize.

Although we do not critique their methods and analysis of fecal stanols, White and colleagues do not consider alternative hypotheses for the way natural and cultural processes may affect the accumulation of fecal stanols in lake sediments. For example, they do not consider the possibility that stanol-enriched runoff from archaeological sites in the Horseshoe Lake watershed or the erosion of stanol-enriched alluvial deposits from its tributaries could lead to contributions of legacy stanols into Horseshoe Lake. Based on studies of the persistence of stanols in soils (Bull et al. Reference Bull, Lockheart, Elhmmali, Roberts and Evershed2002; Simpson et al. Reference Simpson, van Bergen, Perret, Elhmmali, Roberts and Evershed1999), it is possible that stanols could continue to be transported within the Horseshoe Lake watershed well after their initial deposition by humans. Additionally, not enough is known about how stanols accumulate within lake basins. A modern study of stanol concentrations in lake sediments before and after the release of human waste showed that stanol ratios decline in sediments deposited after the implementation of pollution controls. Values, however, remained elevated compared to prepollution conditions, and they displayed greater variability between samples than ratios before pollution occurred (Tse et al. Reference Tse, Codling, Jones, Thoms, Liber, Giesy, Wheater and Doig2014). Furthermore, White and colleagues hypothesize that palynological evidence for expansion of grasslands and increased charcoal concentrations in post-1400 sediments from Horseshoe Lake may represent anthropogenic burning of vegetation, yet they do not address how these changes to land cover in the watershed might impact the mobilization of stanol-enriched sediments from earlier time periods. Consequently, although the correlation of fecal stanol concentrations to the general population history of Cahokia may be worthwhile, using fecal stanol concentrations as a proxy for the post-1400 American Bottom population is problematic, particularly in light of alternative interpretations of sedimentation histories of Horseshoe Lake (Pompeani et al. Reference Pompeani, Hillman, Finkenbinder, Bain, Correa-Metrio, Pompeani and Abbott2019). Additional studies of watershed hydrology and site formation processes relative to the deposition, transport, and sedimentation of stanol-enriched sediments are needed.

Finally, White and colleagues imply that their findings rewrite the history of the post-1400 American Bottom region and Vacant Quarter area. In fact, archaeologists have long known that both the American Bottom region and Vacant Quarter were never fully abandoned, which, interestingly enough, the authors acknowledge in the article (White et al. Reference White, Munoz, Schroeder and Stevens2020:264, 270). Although we agree with their claim that the “vanishing Indian myth” is real, troublesome, and perpetuated by public misperceptions and popular literature, White and colleagues imply that anyone (including archaeologists) who acknowledges a minimal AD 1500–1700 native population in the American Bottom region and Vacant Quarter accepts and perpetuates the myth. We suggest instead that native migrations, abandonments, and resettlements were common throughout North America's precolumbian history and allowed native groups to persist in the face of environmental, social, political, and religious change (Ethridge and Hudson Reference Ethridge and Hudson2002).

The evidence presented by White and colleagues does not support a native population increase in the post-1400 American Bottom region. Their narrative conflicts with abundant archaeological and historical data obtained from the region. Although White and colleagues provide an interesting new line of evidence, we argue that it does not overturn interpretations based on data acquired from over 50 years of intensive archaeological and historical research, especially when so little is known regarding potential processes that affect fecal stanol ratios in lake sediments. It will require far more work to refine and understand how these data fit within the broader precontact history of the American Bottom region, and we hope that this additional work will lead to a better integration of sedimentary paleoecological data with future archaeological research projects.