The Mississippian Emergence

6. The Emergence of Mississippian Culture in the American Bottom Region

John E. Kelly Chapter 6 The Emergence of Mississippian Culture in the American Bottom Region INTRODUCTION East of the present day city of St. Louis, Missouri, the valley of the Mississippi River abruptly broadens to form the American Bottom, an area of approximately 800 sq km, which witnessed, from A.D. 600-1100, the development of the most complex prehistoric sociopolitical system known north of Mexico. In this chapter, I want to review previous explanatory models for this developmental process, and to offer an alternative explanation . In order to discuss such developmental explanations , however, it is necessary to first provide an environmental, temporal, and spatial context for the Mississippian emergence in the American Bottom region , and to provide a brief outline of the cultural historical framework for the five-century span in question. Location and Environmental Setting When expanded to include the adjacent upland drainage catchment areas of Mississippi River tributaries (Fig. 46), the "greater American Bottom" region encompasses considerable environmental diversity and a wide range of inorganic and organic resources. Forming the western boundary of the American Bottom proper, the Mississippi River has shaped and reshaped its landforms since the end of the Pleistocene. As such the river has had a significant effect on the overall configuration of the biotic communities of the area. Bordering the current channel and having a maximum width of 4 km, is a low terrace zone made up of a parallel series of ridges and swales produced by the river's relatively recent downcutting and incising. Clearly demarcated between the present day towns of Columbia and Cahokia, Illinois, as a result of geomorphological research associated with the construction of Interstate 270 (Figs. 17, 46; White 1983:9), the Lunsford-Pulcher terrace, which covers a considerable portion of the American Bottom, contains a complex series of superimposed abandoned channel meander loop oxbow lakes that mark the river's changing course from about 8000-1000 B.C. (cf. Munson 1974; Kelly et al. 1979; White et al. 1984). The Wood River Terrace, which dates to the end of the Pleistocene, is primarily restricted to the northeast corner ofthe American Bottom (Hajic 1987). An extensive area across the northern floodplain may represent the filled channel for this terrace. It is incised by a series of meander loop oxbow lakes, including Long Lake, Edelhardt Lake, and McDonough Lake. Smaller terrace sequences, presumably related to this feature, can be found at a number of the valley openings along the eastern margins of the valley (e.g., Palmer Creek Terrace , Milner 1982). Colluvial veneer and alluvial fan areas located at the base of the bluffs form the final major geomorphological element of the American Bottom (Fig. 46; White et al. 1984). These are a product of redeposition from erosional and stream processes associated with the uplands and hence are superimposed on the floodplain. The biotic communities (Fig. 47) of the American 113 ll4 Kelly THE AMERICAN BOTTOM ca. 1800 KUom" ef ' KEY: Fig. 46. The American Bottom. Bottom were quite diverse during late prehistory, with reconstructions (largely restricted to the area of the American Bottom north of Dupo, Illinois) based on the early twentieth-century studies of Hus (1906) and Telford (1927), along with the early nineteenth-century land records of the U.S. Government (Gregg 1975; Welch 1975). As noted by Johannessen (White et al. 1984:39), the factors effecting the development of these communities include elevation, degree of annual submergence , and other aspects of drainage. The major communities within the floodplain are the river edge zone, subject to annual submergence; the floodplain forest zone, with two linear elevation subzones (Welch 1975); the lake, slough, and pond zone, which includes the low wet areas adjacent to these aquatic areas; the bottomland prairie, which was quite The Emergence of Mississippian Culture in the American Bottom Region 115 UTM Nineteenth 1 Century ~~Ij~ Vegetation Zones \ of the American Bottom ADAPTED fROM GREGG (975), WelCH l\9nl ~ RIVER EDGE ZONE mm IIIIIII BOTTOMLAND PRAIRIE ZONE W%. BOTTOMLAND OAKHICKORY fOREST ZONE HILLSIDE - TALUS SLOPE fOREST ZONE -UPLAND fOREST ZONE UPLAND OAK-HICKORY fOREST ZONE t'I',I,I, ,I,',',', UPLAND PRAIRIE ZONE Fig. 47. The biotic communities of the upper American Bottom. extensive at the time of land survey; and the floodplain oak-hickory zone, restricted to the higher and drier portions of the floodplain. The physiographic units that are transitional to the uplands include a distinct assemblage of the woody...