Cahokia and Other Mississippian Period Centers, the Third Moundbuilding Epoch

Today at Cahokia Mounds State Park in Collinsville, Illinois, one can stand atop the highest mound and see the skyline of St. Louis, Missouri, eight miles to the west on the opposite side of the Mississippi River. From about A.D. 900 to 1250, this site was the preeminent center of Eastern North America, the largest and presumably the most powerful center north of Mexico (Illustration 13). The 100-foot-high mound at its center is the world's largest earthwork, and in 1492 it was the third largest structure of any kind in the Western Hemisphere. (The two larger structures were—and are—in Mexico: the Temple of the Sun at Teotihuacan and the Temple of Quetzalcoatl at Cholula.) One thousand feet long and 700 feet wide, the site covers more than 15 acres. When Cahokia was at the peak of its development around A.D. 1200, whoever stood atop this mound could have counted more than 100 other mounds in the surrounding 5.8-square-mile site. ¹ At least in terms of size, Cahokia was quite comparable to its Mexican contemporary, Tula, the capital of the Toltecs, which covered about 5.6 square miles.