The Ohio History Center in Columbus, Ohio has a major display Indigenous Wonders of Our World which describes the ancient Ohio ceremonial earthworks. The exhibit recognizes the tremendous skill that it took to design and construct these incredible pieces of architecture.
The exhibit focuses on eight earthworks which are unique in the world. According to the display:
“Two thousand years ago, in the land we now call Ohio, the ancestors of American Indian people built vast earthworks. Some of these earthworks had precise geometric shapes, and many were aligned to the rising and setting of the sun and moon.”
The earthworks are prehistoric meaning that they were constructed prior to written histories. Unfortunately, the 2,000 years of oral traditions, which might have provided additional insights into the cultural meanings and use of the earthworks has been mostly erased through the efforts of European colonialization. Today, our understanding of the earthworks is based on archaeology and collaboration with tribal elders.
According to one display:
“The American Indian people who were part of this mound-building heritage built three main types of earthworks: mounds, geometric enclosures and hilltop enclosures. The earthworks were ceremonial and religious spaces, not walled cities or forts.”
There are more than 2,000 mounds and earthworks in Ohio and of these, 238 are geometric enclosures.
The dots on this map show the locations of the mounds and earthworks in Ohio.
The soil used to construct the earthworks was carried to the site in wicker baskets and then dumped.
With one exception, the eight earthworks depicted in the display have astronomical orientations. According to the display:
“The ancient American Indians who built these amazing earthworks, like other ancient cultures, sometimes designed their architecture so it lined up with the rising and setting of the sun and moon at key positions in their cycles.”
These cycles included the solar cycles of solstices and equinoxes and the 18.6-year lunar cycle. According to the display:
“The American Indian ancestors who built these structures understood the complex cycles of the sun and moon. The earthworks demonstrate their genius and mastery of astronomy, architecture and mathematics.”
Today we do not know the ancient names of the earthworks—they currently carry modern names—nor do we know their meanings for the cultures who built them. According to the display:
“We do not know the significance of certain shapes and sizes to the builders of these earthworks. But the fact that they were built to such similar dimensions across the Ohio Valley suggests a special meaning.”
According to the Tribal Notes on the display:
“We may never fully understand why these locations were chosen, but the structures found on them suggest they held meaning for the people who once lived here. The precision of each site suggests they were chosen for their locations on the greater landscape and alignment with seasonal shifts in the sun and moon.”
According to another Tribal Note:
“The Earthworks’ spiritual purpose will remain a mystery kept by the Ancestors. We look at the structures and find universal connections from the night skies and seasonal equinoxes. Although other large structures aligning with the stars and Earth’s seasonal cycles are found across the planet, these Earthworks are unique to the Ancestors of the Woodland people. The ceremonies, their words or songs, dances and tributes are lost to time with only the surviving material culture, many examples of which you will find here remain. The artifacts found at these Hopewell sites suggest long distance trade and communication between distant groups of people. Perhaps they met at these locations at particular times of the year to trade and maintain alliances. Or, to give thanks and tribute for bountiful hunts and harvests. The mystery is part of the enigma of these locations, and why they must be preserved and protected.”
Shown below are the site plans for the eight earthworks and, with one exception, the astronomical orientations of the site.
Hopewell Mound Group
Near Chillicothe, Ohio, the Hopewell site contains thirty-eight earthen mounds within a rectangular earthen enclosure which enclosed 110 acres. In her book America Before the European Invasions, Alice Beck Kehoe writes:
“Overall, Hopewell is the earliest civilization to impress Euroamerican archaeologists with displays of wealth objects reminiscent of European concepts of wealth and status displays.”
Hopewell is an example of a civilization without cities. The Hopewellians lived in small, dispersed villages.
According to the display:
“Two thousand years ago, between A.D. 1 and 400, groups of American Indians living in the Ohio valley had a unique cultural tradition. These people lived in small, scattered communities but periodically gathered together to build vast earthworks. Their artisans used materials, such as copper and sea shells gathered from distant places, to create ceremonial items. Some of these raw materials came from more than 1,700 miles away.”
According to the display:
“Mound 25 at Hopewell Mound Group was the largest single mound in Ohio built by these Ancestors and contained about 1.5 million cubic feat of soil; something like 4.8 million basket loads of soil!”
Seip Earthworks
The Seip Earthworks has two immense circles and a 27-acre square with astronomical alignments. In includes a burial mound which measured 240 feet by 160 feet by 30 feet high.
According to the display:
“Seip Earthworks, which has a volume of 57,726 cubic meters, would take 100 people less than two years to build if they worked on it for 170 days per year during the non-winter months.”
The Seip-Pricer burial mound measured 240 feet by 160 feet by 30 feet high. The mound was excavated by the Ohio Historical Society in 1925 and many artifacts were recovered.
Fort Ancient
On a hilltop in Southern Ohio is Fort Ancient, an archaeological site characterized by a number of earthworks which reach a height of about 23 feet.
According to the display:
“There are an estimated 15 million cubic feet of soil that make up the earthen walls of the Fort Ancient Earthworks. If a basket can hold 30 pounds of soil, it would have taken 125 million baskets to create Fort Ancient.”
Octagon Earthworks
The Octagon Earthworks has eight walls, five to six feet high, which are each about 550 feet long.
Great Circle Earthworks
The Great Circle Earthworks is nearly 1,200 feet in diameter. The walls are eight feet high and surround a moat which is five feet deep.
Hopeton Earthworks
The Hopeton Earthworks has a large, irregular square with rounded corners and a slight outward curvature in its northeastern face and a nearly perfect circle. The two enclosures have nearly equal areas. The walls around the square were approximately twelve feet high and nearly fifty feet wide. The walls around the circle were about five feet high.
High Bank Works
The major features of this site are a circle and an octagon, each of which are approximately 1,000 feet in diameter. Within the octogen there were eight small mounds corresponding to the eight intersecting points of the outer walls.
Mound City Group
The Mound City Group has 25 mounds surrounded by a low earthen wall which is about four feet high. The mounds ranged in height from about three feet to 18 feet.
More Ancient America
Ancient America: Hopewell Offerings #1 (museum tour)
Ancient America: Hopewell Offerings #2 (museum tour)
Ancient America: Linking people to the cosmos in ancient Ohio
Ancient America: A very short overview of the Fort Ancient tradition
Ancient America: A very brief overview of the Adena moundbuilders
Ancient America: Effigy Mounds
Ancient America: A very brief overview of the Hopewell moundbuilders