Last major prehistoric cultural development in North America, с AD 800–1550.
It spread over much of the southeast and the mid-continent, especially in the major river valleys. It was based on intensive cultivation of corn, beans, squash, and other crops. Each large town dominated a group of satellite villages. Each had a central ceremonial plaza with one or more pyramidal or oval earthen mounds surmounted by a temple, a pattern indicating a connection to Central America. The immense Cahokia Mounds near present-day Collinsville, Ill., U.S., was the culture's largest urban centre. Craftwork was executed in copper, shell, stone, wood, and clay. The culture had already begun to decline by the time Europeans first penetrated the southeast. See also Woodland culture .