Late Woodland, to ad 1600
A prime enigma in the prehistory of the northern Midwest are the effigy mounds throughout southern Wisconsin, built in the early Late Woodland period, mid-eighth to mid-eleventh centuries ad. Oneota is the name archaeologists use for the dominant type of northern Midwest agricultural villages: whether they were colonists coming up the Mississippi, Illinois, and Rock Rivers, or local Late Woodland societies taking up intensive maize agriculture with its “sisters” squashes and beans, or both, can’t always be deciphered. One school of archaeologists sees continuity of artifacts from Middle Woodland, positing Iroquois in their Northeast homelands for two thousand years. Opposed archaeologists are more impressed with apparent discontinuities: a shift in pottery technique from coil-built to patched-on clay in early Late Woodland, substantial maize–beans–squash agriculture appearing in the twelfth century, and fortified towns in the later thirteenth century. “Late Woodland” has been a “default” category, those Late Prehistoric Eastern Woodlands sites and associated artifacts that don’t show Mississippian characteristics.