The Hopewell people built this great ceremonial center about the time Christianity blossomed, and it reflects a flourishing religion and culture. Like the great cathedrals, mosques, and temples of the world, Hopewell Mound Group was a place of ceremony, celebration, and religious expression. Its massive earthworks once included 3 miles of earthen walls and some 40 mounds covering over 130 acres. The Hopewell built these ancient earthworks with great care, using sharpened sticks, antler picks, and bone hoes to dig the clay, sand, and gravel needed to form the embankments and mounds. Completing the earthworks required a large labor force and generations of workers. Many of the most impressive Hopewell culture artifacts were found here, including 8,000 hand-chipped flint discs ceremonially buried by the Hopewell nearly 2,000 years ago and unearthed by archeologist Warren Moorehead in 1891. The earthwork's outline was formed by a large enclosure connected to a smaller square enclosure, and even the smaller square was large enough to contain all of Mound City Group, including its 24 mounds, embankments, and borrow pits.