Outside of the Southwest, Northern America’s early agriculturists are typically referred to as Woodland cultures. This archaeological designation is often mistakenly conflated with the eco-cultural delineation of the continent’s eastern culture areas: the term Eastern Woodland cultures refers to the early agriculturists east of the Mississippi valley, but the term Eastern Woodlands refers to the Northeast and Southeast culture areas together.

As in the Southwest, the introduction of corn in the East (c. 100 bce) did not cause immediate changes in local cultures; Eastern Archaic groups had been growing locally domesticated plants for some centuries, and corn was a minor addition to the agricultural repertoire. One of the most spectacular Eastern Woodland cultures preceding the introduction of maize was the Adena culture (c. 500 bce–100 ce, although perhaps as early as 1000 bce in some areas), which occupied the middle Ohio River valley. Adena people were hunters, gatherers, and farmers who buried their dead in large earthen mounds, some of which are hundreds of feet long. They also built effigy mounds, elaborate earthen structures in the shape of animals.

This tradition of reshaping the landscape was continued by the Hopewell culture (c. 200 bce–500 ce) of the Illinois and Ohio river valleys. Hopewell society was hierarchical and village-based; surplus food was controlled by elites who used their wealth to support highly skilled artisans and the construction of elaborate earthworks. An outstanding feature of Hopewell culture was a tradition of placing elaborate burial goods in the tombs of individuals or groups. The interment process involved the construction of a large box-like log tomb, the placement of the body or bodies and grave offerings inside, the immolation of the tomb and its contents, and the construction of an earthen mound over the burned materials. Artifacts found within these burial mounds indicate that the Hopewell obtained large quantities of goods from widespread localities in North America, including obsidian and grizzly bear teeth from as far away as the Rocky Mountains; copper from the northern Great Lakes; and conch shells and other materials from the southeast and along the coast of the Gulf of Mexico. Sites in Ohio were particularly important distribution centers, controlling ceremonial goods and special products over a wide area. Evidence for this so-called Hopewell Interaction Sphere rapidly faded after about 400 ce, although Hopewell traditions continued for another century and Eastern Woodland cultures as a whole persisted for another 300 years.

Mississippian cultures

About 700 ce a new cultural complex arose in the Mississippi valley between the present-day cities of St. Louis and Vicksburg. Known as the Mississippian culture, it spread rapidly throughout the Southeast culture area and into some parts of the Northeast. Its initial growth and expansion took place during approximately the same period (700–1200) as the cultural zenith of the Southwest farmers. Some scholars believe that Mississippian culture was stimulated by the introduction of new concepts, religious practices, and improved agricultural techniques from northern Mexico, while others believe it developed in place as a result of climactic change and internal innovation.

Whatever the origin of particular aspects of Mississippian life, the culture as such clearly developed from local traditions; between 700 and 1000, many small Eastern Woodland villages grew into large towns with subsidiary villages and farming communities nearby. Regionally delimited styles of pottery, projectile points, house types, and other utilitarian products reflected diverse ethnic identities. Notably, however, Mississippian peoples were also united by two factors that cross-cut ethnicity: a common economy that emphasized corn production and a common religion focusing on the veneration of the sun and a variety of ancestral figures.

One of the most outstanding features of Mississippian culture was the earthen temple mound. These mounds often rose to a height of several stories and were capped by a flat area, or platform, on which were placed the most important community buildings—council houses and temples. Platform mounds were generally arrayed around a plaza that served as the community’s ceremonial and social center; the plazas were quite large, ranging from 10 to 100 acres (4–40 hectares). The most striking array of mounds occurred at the Mississippian capital city, Cahokia, located near present-day St. Louis; some 120 mounds were built during the city’s occupation. Monk’s Mound, the largest platform mound at Cahokia, rises to approximately 100 feet (30 meters) above the surrounding plain and covers some 14 acres (6 hectares).

In some areas, large, circular charnel houses received the remains of the dead, but burial was normally made in large cemeteries or in the floors of dwellings. Important household industries included the production of mats, baskets, clothing, and a variety of vessels for specialized uses, as well as the creation of regalia, ornaments, and surplus food for use in religious ceremonies. In some cases, particular communities seem to have specialized in a certain kind of craft activity, such as the creation of a specific kind of pottery or grave offering. Ritual and religious events were conducted by an organized priesthood that probably also controlled the distribution of surplus food and other goods. Core religious symbols such as the weeping eye, feathered serpent, owl, and spider were found throughout the Mississippian world.

As the Mississippian culture developed, people increased the number and complexity of village fortifications and often surrounded their settlements with timber palisades. This was presumably a response to increasing intergroup aggression, the impetus for which seems to have included control of land, labor, food, and prestige goods. The Mississippian peoples had come to dominate the Southeast culture area by about 1200 and were the predominant groups met and described by Spanish and French explorers in that region. Some Mississippian groups, most notably the Natchez, survived colonization and maintained their ethnic identities into the early 21st century.

Plains Woodland and Plains Village cultures

Archaic peoples dominated the Plains until about the beginning of the Common Era, when ideas and perhaps people from the Eastern Woodland cultures reached the region; some Plains Woodland sites, particularly in eastern Kansas, were clearly part of the Hopewell Interaction Sphere. Beginning between about 1 and 250 ce and persisting until perhaps 1000, Plains Woodland peoples settled in hamlets along rivers and streams, built earth-berm or wattle-and-daub structures, made pottery and other complex items, and raised corn, beans, and eventually sunflowers, gourds, squash, and tobacco.

On the Plains a regional variation of the favorable agricultural conditions that elsewhere supported the most elaborate forms of culture also fostered a marked increase in settlement size and population density; during this period (locally c. 1000–1250) the hospitable areas along most major streams became heavily occupied. These and subsequent village-dwelling groups are known as Plains Village cultures. These cultures were characterized by the building of substantial lodges, the coalescence of hamlets into concentrated villages, and the development of elaborate rituals and religious practices. Having expanded their populations and territories when conditions were favorable, a period of increasing aridity that began about 1275 caused hardship and in some cases armed conflict among these peoples; at the early 14th-century Crow Creek site (South Dakota), for instance, nearly 500 people were killed violently and buried in a mass grave.

Some village-dwelling peoples sustained their communities through this difficult period, while others retreated eastward and returned when the climate had improved. The descendents of the early Plains Village cultures, such as the Sahnish, Mandan, Hidatsa, Muscogee, Wichita, Pawnee, and Ponca, greeted European explorers from the 16th century onward and continued to live on the Plains in the early 21st century.

Between 1500 and 1700, the farming peoples of the western and southern Plains, such as the Apache and Comanche, took up a predominantly nomadic, equestrian way of life; most continued to engage in some agriculture, but they did not rely on crops to the same extent as settled village groups. From the early 18th century onward, a number of agricultural groups from the Northeast culture area left their forest homes for the Plains and completely substituted equestrian nomadism for agriculture; perhaps the best known of these were the Oceti Sakowin and Cheyenne, whose traditional territory had been in present-day Minnesota.