The construction and use of Cahokia's grand plaza

Excavations were conducted in 1997 and 2004 along a 1200 m-long waterline corridor through the middle of the central plaza at Cahokia, the largest and possibly earliest Mississippian period (A.D. 1050-1350) population center in North America. These excavations provide a unique window into previously unknown aspects of the construction and use history of this singular monumental space. Built as the centerpiece of Cahokia's city plan in the middle of the 11th century A.D., the plaza appears to have been more spacious than the most generous previous estimate. The labor needed to build one-quarter to one-third of this plaza may have exceeded 10,000 person-days. Once built, evidence points to the possible existence of a gallery of upright posts and small buildings in front of Monks Mound, the largest earthen pyramid in the center of the site complex. By the 13th century, domestic buildings appear to have lined the plaza edges.