The varying cultures collectively called Mound Builders were inhabitants of North America who, during a 5,000-year period, constructed various styles of earthen mounds for religious and ceremonial, burial, and elite residential purposes. These included the Pre-Columbian cultures of the Archaic period; Woodland period (Adena and Hopewell cultures); and Mississippian period; dating from roughly 3500 BCE (the construction of Watson Brake) to the 16th century CE, and living in regions of the Great Lakes, the Ohio River Valley, and the Mississippi River valley and its tributary waters.[1]