1100 A.D.
23000
1100
Dirt from the smaller mounds within the city limits was later used by East St. Louis as fill for dikes and levees.
The Great Mound on present-day Collinsville Road was built over a period of 300 years. There are depressions in the surrounding area which indicate that the natives created "borrow pits" as supply sources for the dirt that was used. Its base covers more than fourteen acres, and it contains about 22 million cubic feet of earth, making it the largest man-made structure north of Mexico when the Pilgrims landed at Plymouth in 1620.
A massive building, 105 feet long by 48 feet wide by 50 feet high, once stood at the top. Here the Indians' principal ruler lived, conducted ceremonies, and governed the people below. At its zenith, the city contained about 20,000 inhabitants. The Mississippians built a wooden wall 12 to 15 feet high around 300 acres of the central city.
