Mississippian period (archaeology)

The Mississippian period is an archaeological cultural era in the Southern United States and nearby parts of the Eastern Woodlands, lasting from the late 900s into the 1500s. It came after the Late Woodland period and ended with the colonial-era Mississippian shatter zone. The Mississippian people were known for theocratic rule, large population centers, and a heavy reliance on maize farming. This differed from the earlier Woodland peoples, who used crops from the Eastern Agricultural Complex and built mostly burial mounds. The Mississippian period is split into Early, Middle, and Late phases.

Despite major shifts in society and politics, the break from the Woodland period was not total. Maize was central, but the old Eastern Agricultural Complex crops were still grown. The flat-topped platform mound, once seen as a uniquely Mississippian feature, actually dates back to the Archaic period, though building structures on top of these mounds does appear to be unique to Mississippians. Most Mississippian groups kept the Hopewell clan system, where each clan acted more like a ritual society than a simple family group, and travelers could get hospitality from a fellow clan member even thousands of miles away.

The city of Cahokia was founded in 1050 and likely had at least 22,400 people at its peak around 1124. Archaeologists think it was a planned social and religious project, with large mounds built by a mix of Caddoan, Natchezan, Muskogean, and Dhegiha Siouan peoples. Between 1050 and 1150, Cahokians briefly set up missionary outposts as far as 500 miles north. These failed and were rejected by local Woodland groups, but other Cahokian projects had more success, such as Angel Mounds, which served as a pilgrimage site. The end of the Medieval Climate Anomaly (roughly 900 to the early 1100s) and a decades-long drought from 1150 to 1200 in Illinois brought political instability.

This instability caused about half of Cahokia’s population to leave for the Nashville area (likely ancestors of the Koasati people), which peaked around 1275, and several thousand more moved to places like Angel on the Ohio River and Etowah in the Appalachians, starting the Middle Mississippian period. Many Mississippian mound centers outside Cahokia’s influence grew in importance, such as Moundville in Alabama, the Yazoo basin in Mississippi, and the Oconee basin in Georgia. As elites at these sites attracted more exotic trade goods, new religious ideas from the west arrived around 1300, notably the Datura Ritual Complex.

The Late Mississippian period (1400–1600) saw less elaborate but territorially larger paramount chiefdoms. These functioned less like the Middle Mississippian complex-chiefdoms with a strong center and weaker periphery, and more like confederations of mound sites led by a paramount, a *primus inter pares* called the "Gran Cacique" by Spanish settlers. Many settlements became more nucleated, defenses were strengthened, and archery technology advanced. Entire river basins, like the Savannah River, turned into "Vacant Quarters"—sparsely settled buffer zones between growing paramount chiefdoms.

**History**

**Emergent Mississippian/Terminal Late Woodland (c. 900 – c. 1000)**

Mississippian peoples came from earlier Woodland groups, inheriting the Hopewell clan system, Hopewell units of measurement, and reusing some Hopewell mound centers. The Post-Hopewell Late Woodland period saw new bow and arrow technology, more maize consumption, more elaborate platform mound construction, and new political forms. The latter half of this period, from 900 to 1000, is called the Emergent Mississippian or Terminal Late Woodland. It continued many Late Woodland trends but is notable for the first summit structures on platform mounds, the start of shell-tempered pottery, and expanding trade networks. It is also set apart by the growth of Cahokia during this time.

**Early Mississippian period (c. 1000 – c. 1200)**

The Early Mississippian period was mainly defined by the growth and peak of Cahokia. Including downtown Cahokia near Collinsville and the East St. Louis precinct, this urban center likely reached its highest population and power around 1124, with at least 22,400 people and possibly a few thousand more in St. Louis. Most construction happened during the Edelhardt phase (1000–1050) and Lohmann phase (1050–1100). Archaeologists believe it was a planned social and religious project, with towering earthen pyramids built by a mix of Caddoan, Natchezan, Muskogean, and Dhegiha Siouan peoples. It may have been linked to astronomical events like Halley's Comet or SN 1054.

Between 1050 and 1100, Cahokians briefly set up missionary outposts in the Midwest up to 560 miles north, such as Trempealeau Mounds, Aztalan, and the Apple River valley. Various theories exist for why Cahokians came and were allowed to stay in these areas. For the Cahokians, the main reasons were likely spreading their way of life and religion.