The Adena, Ohio's first mound builders

At a glance

A house gives its name to a culture

By around 800 BC, descendants of Ohio Valley Archaic hunter-gatherer bands began doing something new: building conical earthen mounds over their honored dead, again and again, in the same places, generation after generation. Archaeologists call the resulting tradition the Adena culture, a term of pure archaeological convenience that no ancient person ever used for themselves. Its range runs across southern and central Ohio, Kentucky, West Virginia's Kanawha Valley, southeastern Indiana and southwestern Pennsylvania during the Early Woodland period, roughly 2,800 to 2,000 years before present, according to Ohio History Central.

The name comes from a single Ross County hilltop. In 1798, Thomas Worthington, a Virginian who had freed his own slaves the year before, bought Scioto River bottomland near the new town of Chillicothe, land that already held a large, tree-covered burial mound. In 1805 he commissioned architect Benjamin Henry Latrobe to design a sandstone house on the hill above; the house went up in 1807, and in 1811 Worthington renamed the estate "Adena," a word his own diary says he found in a book on ancient history, meaning places "remarkable for the delightfulness of their situations."

By 1901 the estate had passed out of the Worthington family to Joseph Froehlich, who wanted the mound's fine farmland back and contracted with the Ohio State Archaeological and Historical Society to remove it, hauling the fill into a nearby railroad cut. William C. Mills, the Society's curator, ran that summer's excavation. He measured the mound at 26 feet high, with a 445-foot circumference, and took it down in five-foot sections from the top to the base, photographing every skeleton and structural change in place, publishing the full report in the Ohio Archaeological and Historical Quarterly the following year, according to Mills's original 1902 report. Mills found the mound had gone up in two distinct episodes: an original, 20-foot mound holding 21 burials wrapped in bark or woven fabric inside log-lined tombs roomy enough in places for a person to stand upright, and a later, lighter-colored enlargement that extended the mound's base and added 12 more burials with far fewer grave goods. Because the mound's artifacts and burial style were treated as a representative sample of a whole regional pattern, it became the "type site," and its name — taken from Worthington's estate — was applied to every site sharing that pattern, from Ohio to Kentucky and West Virginia.

Radiocarbon work a century later sharpened the date. Mills had saved plain strips of black-locust bark that had lined some of the tombs, and when the Ohio History Connection later sent surviving bark and textile fragments out for testing, the results, reported in January 2014, placed the mound's construction at about 100 BC to AD 40, replacing an older estimate that had spread from 700 BC to AD 100. That the type site itself dates so late in the Adena sequence is a reminder that "Adena" spans many centuries, not one moment: the culture as a whole is usually bracketed from about 800 BC to AD 1-100, though Ohio History Central and other sources differ on the exact start date by up to three centuries.

The pipe that became state law

Near one burial's left hand, Mills recovered an 8-inch effigy pipe, carved from a clay resembling the fire-clay of Scioto County, that would become known simply as the Adena Pipe. It depicts a nude human male figure, ear spools in his lobes, wearing only a loincloth tied at the back, with a serpentine scroll design on the front; the bowl opening sits between the figure's feet, and smoke draws up through the body to a mouthpiece built into the headdress.

The pipe sat in Ohio's historical collections for over a century before a years-long campaign, begun by teachers Charlotte Stiverson and Tracy Kessler and their students at the Columbus School for Girls, pushed to make it an official state symbol, according to the Ohio History Connection. Ohio Revised Code 5.075, enacted as Senate Bill 33 of the 130th General Assembly, names "the artifact known as the Adena pipe... discovered in 1901 by William C. Mills within a burial mound near Chillicothe" as Ohio's official state artifact, effective August 15, 2013, according to the statutory text. Governor John Kasich signed the bill, and the Ohio History Connection held a signing celebration attended by the bill's student advocates and its legislative sponsors.

Ohio's mounds, and the biggest one of all

Miamisburg Mound, on a bluff over the Great Miami River in Montgomery County, is Ohio's largest surviving conical mound: 65 feet tall, 800 feet in circumference, roughly 54,000 cubic yards of earth, built sometime between 800 BC and AD 100, according to the Ohio History Connection. A historical marker records that the mound originally stood 68 feet high before a partial 1869 excavation reduced it: workers sank a vertical shaft from the summit to the base, cross-cut by two horizontal tunnels, and found a bark-covered skeleton 8 feet down and an empty log-lined vault 28 feet below that, with layers of ash and stone along the shaft suggesting the mound was built in several stages, according to the Historical Marker Database. Dayton inventor and General Motors executive Charles Kettering bought the mound and made it a public park in 1920; it passed to the Ohio Historical Society for preservation in 1929.

Ohio's second-largest conical mound stands in Enon, Clark County: over an acre in footprint, 574 feet around and 40 feet high, which a local historical marker says took an estimated one million basket-loads of riverbed soil to raise. A separate marker records an undocumented 19th-century dig by "young men" who found only a stone-lined chamber at the bottom, an amateur disturbance with no professional follow-up and no surviving artifact record.

The largest Adena mound anywhere in the world, though, stands outside Ohio, in Moundsville, West Virginia: Grave Creek Mound. Road engineers measured it in 1838 at 69 feet high with a base of roughly 292 to 295 feet; a modern survey gives 62 feet and 240 feet, a difference most plausibly explained by a century and a half of settling and erosion. Its builders moved more than 60,000 tons of earth in successive stages across roughly a century, around 250 to 150 BC, based on burials found at different levels, according to Wikipedia's account of Grave Creek Mound. Landowner Jesse Tomlinson's nephew Abelard Tomlinson and his brother-in-law Thomas Biggs tunneled three shafts into the mound starting March 19, 1838, breaking into a lower burial chamber about 111 feet in that held two burials and roughly 650 beads, then a second, upper chamber found June 9, 1838, with about 1,700 ivory beads, 500 sea shells and five copper bracelets. Tomlinson then opened the tunnels as a paying museum inside the mound itself, charging admission until he gave it up in 1847. A small inscribed sandstone tablet recovered during the dig, the "Grave Creek Stone," was for decades cited as proof of ancient literate visitors to North America; modern scholars consider it a hoax. Local women of the Wheeling chapter of the Daughters of the American Revolution saved the mound from development in 1908, West Virginia bought the site in 1909, it became a National Historic Landmark in 1964, and the state opened the Delf Norona Museum alongside it in 1978.

A quarter mile from the Adena Mound itself, Story Mound, 19.5 feet high on a 95-foot base, was excavated in 1897 by Clarence Loveberry, whose dig turned up the first documented example of a circular Adena timber building underneath a mound, along with a skeleton surrounded by jewelry, beads and projectile points, according to the Ohio History Connection. Ohio acquired the site in 1950, and it remains open to the public today.

Houses, "sacred circles" and carved tablets

Away from the mounds, Adena communities lived in small, scattered settlements of one or two structures near their gardens. A typical house was circular, 15 to 45 feet across, its walls made of paired posts tilted outward and joined at the top into a cone-shaped roof covered in bark and, in places, wickerwork, according to Wikipedia's account of the Adena culture. The same paired-post technique also produced free-standing timber circles that were not roofed houses at all but open-air ceremonial enclosures, sometimes called "sacred circles." Wikipedia's broader account of Adena mound-building describes a repeating cycle behind many of these structures: a timber mortuary building held the dead and their grave goods, the building was burned, earth was piled directly over the ashes, and a new mortuary structure was placed on top of the new earthwork to begin the cycle again — one reason so many mounds, opened layer by layer, turn out to hold a stack of burials and structures rather than a single interment.

At Kentucky's Wright Mounds, a ridgetop cluster of three conical mounds in Montgomery County excavated in 1937 by University of Kentucky archaeologists, both excavated mounds had been built directly over the remains of one of these paired-post circles — the enclosure came first, was used, and only later was covered by the burial mound, according to the Kentucky Archaeological Survey. Broken ceramic vessels found in the fill between construction phases suggest the builders periodically came back to feast and, perhaps, deliberately break pottery as part of the ritual.

A small, strange class of Adena artifact is the engraved stone tablet: flat pieces of fine-grained stone, usually about 4 to 5 inches by 3 to 4 inches and half an inch thick, carved in deep relief with stylized birds and curvilinear geometric designs. As many as 13 are known from Ohio, Kentucky and West Virginia. The first one described by science, the Cincinnati Tablet, turned up in the fall of 1841 when road-grading crews removed a burial-mound complex near Fifth and Mound Streets in downtown Cincinnati — ground that is a UPS facility today — alongside copper cutouts, galena, mica, shell and copper beads, and bone awls, according to the Cincinnati Museum Center. It was exhibited within weeks at the Western Academy of Natural Sciences, then written up more than a year later in the December 12, 1842 Cincinnati Gazette and the May 1843 American Pioneer. What the tablets were for is still unresolved. Some carry traces of red ochre, and several have deep grooves on the back like a whetstone; the leading guesses are that they were used to stamp designs onto skin, cloth or hide, to outline tattoo patterns, or, for the grooved examples, to sharpen the bone awls and needles used in that tattooing. No single interpretation has been confirmed.

Trade, diet and daily life

Adena burials regularly include materials that could only have arrived by long-distance exchange: copper from the Lake Superior basin, marine shell from the Atlantic and Gulf coasts, and mica from the southern Appalachians, all moved overland and along river routes, chiefly the Ohio River and its tributaries, centuries before wheeled transport or draft animals existed anywhere in North America. These exotic materials appear concentrated in burial and ceremonial contexts rather than everyday trash, one reason archaeologists read them as markers of status or ritual importance rather than ordinary commerce.

Adena people were not full-time farmers. They hunted deer, elk, black bear, woodchuck, beaver, porcupine, turkey, trumpeter swan and ruffed grouse, gathered wild seeds, grasses and nuts, and grew squash, sunflower, sumpweed, goosefoot, erect knotweed, maygrass and tobacco in small garden plots near semi-permanent settlements. This suite of native, independently domesticated plants — the Eastern Agricultural Complex — represents one of only a handful of places in the world where people domesticated crops entirely on their own, without contact with Old World agriculture, beginning around 7,000 calibrated years before present, well before the Adena period itself. Adena people also made Ohio's first widespread clay pottery: thick-walled, grit- or crushed-limestone-tempered vessels, plain or cord/fabric-marked, likely used to cook ground seeds into a gruel — vessels that, unusually for such an important craft, were generally not placed in burials the way pipes, gorgets and ornaments were.

What Adena did not build

Two of Ohio's most famous earthworks are sometimes assumed to be Adena, and neither one clearly is. Fort Ancient, the massive hilltop enclosure in Warren County, is attributed by the National Historic Landmark nomination to the later Hopewell culture, built with digging sticks and shell hoes around 300 BC to AD 250. The unrelated "Fort Ancient culture," a Mississippian-era farming people, only resettled the already-abandoned hilltop around AD 1200 to 1600, long after the Hopewell had left — a shared name, not a shared people. There is no confirmed Adena-period construction phase at Fort Ancient.

Serpent Mound, the quarter-mile effigy earthwork in Adams County, carries its own unresolved dating dispute. A 1991 excavation's radiocarbon dates pointed to construction by the Fort Ancient culture around AD 1025 to 1215. A 2014 Bayesian radiocarbon study, corroborated by a 2019 follow-up, re-dated construction to about 300 BC — squarely in the Adena period — with a repair episode around AD 1100 accounting for the younger dates found in the 1990s excavation, according to Wikipedia's account of Serpent Mound. Ohio archaeologist Brad Lepper has publicly challenged the Adena redating, arguing the 2014 study's early samples came from unreliable soil-core material rather than genuine stratigraphic charcoal, and that the serpent-and-egg imagery fits Fort Ancient iconography better than anything documented for the Adena. Ohio History Connection presents both attributions as live possibilities rather than declaring a winner; Serpent Mound is not confirmed as an Adena site, only argued to be one by a serious minority of the radiocarbon evidence.

From Adena to Hopewell

There is no sharp break between Adena and the Hopewell tradition that followed it. Ohio History Central places the shift around AD 1, when some Adena groups began building larger earthworks and importing more exotic raw materials, while other communities, especially in southwestern Ohio, kept building and living in older Adena ways into the first century AD. Modern radiocarbon work on mixed sites bears this out: Kentucky's Walker-Noe site combines Adena and emerging Hopewell features and dates to roughly 166 BC to AD 125. The change was gradual and regionally uneven, not a single switch flipped in one year across the whole Adena world.

Sources

• Adena Culture, Ohio History Central
• Excavations of the Adena Mound, William C. Mills, Ohio Archaeological and Historical Quarterly, vol. 10 (1902)
• Celebrating Ohio's State Artifact, Brad Lepper, Ohio History Connection, 2013
• Ohio Revised Code 5.075, State artifact
• Miamisburg Mound, Ohio History Connection
• Miamisburg Mound historical marker, Historical Marker Database
• Story Mound, Ohio History Connection
• Wikipedia, "Adena culture"
• Wikipedia, "Grave Creek Mound"
• Wright Mounds, Kentucky Archaeological Survey
• The Story of the Cincinnati Tablet, Cincinnati Museum Center, 2019
• Wikipedia, "Eastern Agricultural Complex"
• Wikipedia, "Serpent Mound"
• Enon Adena Mound marker, Historical Marker Database
• Adena Mound Enon Ohio marker, Historical Marker Database