The southeastern United States as defined in this study encompasses the modern political units of Alabama, Arkansas, the District of Columbia, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, South Carolina, Tennessee, and Virginia. This region, while demarcated by modern political and resource management considerations, closely corresponds to various definitions of a southeastern Native American culture area advanced by anthropologists over the past century. That is, the area contains a number of related societies whose cultural similarities are believed due, in part, to fundamental characteristics of environment and geography, and to a shared history. The Southeast retains such an identity to this day, although precise definitions of what constitutes its boundaries vary somewhat from person to person (see Smith 1986 for a map showing various scholarly definitions of the Native American southeastern cultural area, none of which, however, vary appreciably from one another).
The Southeast roughly corresponds to the lands south and east of the Ohio River and east of the Mississippi River, and from Chesapeake Bay south. It includes two major physiographic zones, the low lying and minimally dissected coastal plains, and the higher and more variegated interior hills, mountains, and plateaus (see also Bense 1994:17). These areas are, of course, subdivided into a number of smaller regions (Fenneman 1938; Hunt 1974) (Figure 1). Thus, the coastal plain includes the Atlantic and Gulf Coastal Plains, with the Mississippi Alluvial Valley sometimes set off within the latter. The interior encompasses the Piedmont, Blue Ridge, Ridge and Valley, Appalachian Plateau, and Interior Low Plateau regions.
Drainages tend to flow to the south and southeast in the Gulf and Atlantic Coastal Plains and Piedmonts, respectively, and to the west and north in the Interior and Appalachian Plateaus. The orientation of these drainages has profoundly shaped movement and interaction throughout prehistory, as well as in the historic period (Anderson 1994; Tanner 1989). The loci of initial human colonization in the Southeast, and the directions these first peoples moved over the landscape, were profoundly influenced by the alignment of major drainages (Anderson and Gillam 2000); early peoples are assumed to have walked the margins or used watercraft directly on these waterways (Anderson 1990a, 1995a; Engelbrecht and Seyfort 1994; Faught 1996; Jodry 1999; Mason 1962; Williams and Stoltman 1965). In the lower Southeast, movement along drainages would have trended from the interior to the coast, in a north-south direction in the Gulf Coastal Plain, and in a roughly northwest-southeast to east-west direction in the Atlantic Coastal Plain. In the interior Midsouth, movement would have been east and west along rivers like the Tennessee, Cumberland, and Ohio and some of their tributaries, as well as north-south into and out from the lower Midwest. While the Appalachian Mountains were likely a major barrier to east-west population movement along the middle Atlantic seaboard, farther south in the Gulf and lower Atlantic Coastal Plains east-west movement would have been easier, and could have proceeded along major ecotones like the Fall Line between the Coastal Plain and Piedmont, or along the coastline itself.
During the period of presumed initial human settlement, some time after the glacial maximum ca. 18,000 rcbp (21,400 B.P.), the Coastal Plain was almost twice its present size due to lowered sea levels. Sea levels rose and fell dramatically in the Late Pleistocene, with vast areas alternately submerged and exposed, something that almost certainly profoundly affected early human settlement. Rapid glacial retreat in the north began during the Bølling, after ca. 12,600 rcbp (14,850 B.P.), and continued with comparatively minor fluctuations until the sudden onset of the Younger Dryas glacial readvance around 10,800 rcbp (12,900 B.P.). Assuming initial human entry occurred sometime during the Bølling or Allerød, these groups would have been faced with a vast but slowly shrinking Coastal Plain, whose shoreline would be trending inland, save for comparatively minor movements in the other direction, during events like the Older Dryas (ca. 12,100-11,950 rcbp; 14,100-13,950 B.P.) and the Inter-Allerød Cold Period (ca. 11,400-11,100 rcbp; 13,400-13,100 B.P.). A major readvance, the Younger Dryas, occurred from ca. 10,800-10,100 rcbp (ca. 12,900-11,650 B.P.), with pronounced cold conditions appearing suddenly, within a human lifetime (Bjorck et al. 1996:1159). If a sudden drop in sea-level occurred (something that needs to be verified), it would have exposed large areas of the previously submerged continental shelf, an area that may have taken some time to revegetate.
The region below the Ohio River is south of the area covered by continental ice sheets during the glacial maximum (Dyke and Prest 1987a, 1987b). Whether glaciers or other permanent ice masses were present in the southern Appalachians or elsewhere in the Southeast during the Late Pleistocene is unknown, but if present they would have likely been quite small, and occurring only during periods of extreme and prolonged cold. Their impact on human settlement, accordingly, would have been minimal. There were no tundra environments in the Southeast, and no major glacial or pluvial lakes (comparable to the large lakes present to the north and in the west at the end of the Pleistocene). As the major river system draining the midcontinent, however, the Mississippi carried vast amounts of glacial meltwater during warming intervals. The volume of water led to the creation of braided stream channels in the lower Mississippi valley, which were abruptly replaced by a meander regime once meltwater discharge ceased (Saucier 1994:45, 93-98). With lowered sea levels, many Late Pleistocene river systems may have been much narrower and more deeply incised than at present. With post glacial sea level rise, silting would have occurred along many channels, burying potential locations for early sites, which in the larger systems may have subsequently been lost to meander scouring (Goodyear 1999a; Knox 1983). Late Pleistocene terraces are often found above modern floodplains, however, rendering detection of surfaces of this period difficult.
High quality knappable stone occurs unevenly over the region, and in fact tends to be uncommon in some parts of the Coastal Plain and Piedmont. Major outcrops of chert occur in parts of the south Atlantic Coastal Plain, in Georgia and South Carolina and the Florida Peninsula, while farther west they tend to occur as gravel deposits in the Coastal Plain portions of Alabama, Mississippi, Arkansas, and Louisiana. Outcrops of high quality chert and novaculite, in large tabular masses, occur in portions of the interior highlands, in the Ouachita and Ozark mountains, and in the interior plateaus. Metavolcanics are known from across the Piedmont, but whether many or only a few key sources saw extensive exploitation is unknown, although evidence currently favors the latter position (Daniel 1998, 2001; Daniel and Butler 1991, Novick 1978). Lower quality cherts, quartz, and metavolcanics are more widespread in the interior, and as gravel deposits in portions of the Coastal Plain, but do not appear to have been the first choice of early populations, particularly those using Clovis technology (Goodyear 1979, 1989).
Boreal conifers like spruce and jack-pine dominated southeastern forests during the full glacial north of latitude 33, from about the vicinity of central South Carolina across to the Arkansas Louisiana line. With the onset of rapid deglaciation in the Bølling, mixed hardwood forests began to move northward from refugia in the lower Southeast. This expansion does not appear to have been affected much by the Younger Dryas readvance (M. Davis 1983:172-73; H. Delcourt and Delcourt 1985:19; P. Delcourt and Delcourt 1981, 1983, 1987, 1991; Jacobson et al. 1987; Overpeck et al. 1992; Steele et al. 1998:292; Watts 1971:687, 1980:195; Watts et al. 1996; T. Webb 1987, 1988; T. Webb et al. 1993). By 10,000 rcbp (11,450 B.P.), hardwood and mixed hardwood-pine forests were present across the entire southeast.
Late Pleistocene fauna in the Southeast encompassed a wide range of extinct and modern animal species. In addition to fauna such as mammoth, mastodon, horse, giant sloth, saber-toothed tiger, and camel, modern animals were also present such as white tailed deer, raccoon, and rabbit. The extent to which extinct fauna were exploited remains unknown, although there is no question they were at least occasionally targeted. The late Pleistocene extinctions were complete by ca. 10,800 rcbp or about 12,750 years ago (Mead and Meltzer 1984; Meltzer and Mead 1983), after which time local human populations had a much narrower array of animal resources to choose from.