Jefferson’s Mound is a manmade formation consisting of raised earth and stones. Such mounds occur throughout the world; in Europe, especially, they are called tumuli, barrows, or kurgans. According to Jefferson, the Rivanna River mound was, in 1784, spheroidal in shape (an imperfectly round sphere, in other words) with a diameter at the base of forty feet. It was seven-and-a-half-feet tall, although Jefferson guessed that in the previous twelve years it had been reduced by plowing from about twelve feet. Around the base of the mound was a five-feet-wide and five-feet-deep ditch likely created by the removal of earth to build up the mound.
Jefferson’s excavation of the mound was provoked by a questionnaire sent late in the American Revolution (1775–1783) by François de Barbé-Marbois of the French delegation to each state in the newly formed United States. The questionnaire asked for information from each state on its commodities, rivers, population, history, natural history, and “Aborigines.” Jefferson’s response, on behalf of Virginia, eventually developed into Notes on the State of Virginia. Regarding “Aborigines,” Marbois asked for their history and their present condition, which Jefferson dutifully answered. He then queried as to any existing Indian monuments. Jefferson wrote: “I know of no such thing existing as an Indian monument: for I would not honour with that name arrow points, stone hatchets, stone pipes and half-shapen images. Of labour on the large scale I think there is no remain as respectable as would be a common ditch for the draining of lands; unless it be the Barrows of which many are to be found all over this country.”
Jefferson went on to describe competing hypotheses concerning these mounds’ function. They may have been battleground cemeteries, for instance, or burial grounds serving local or regional communities. “There being one of these [mounds] in my neighbourhood,” he wrote, “I wished to satisfy myself whether any and which of these opinions were just.”
Based on his analysis of Jefferson’s original edited manuscript pages of Notes on the State of Virginia, the historian Douglas Wilson argues that Jefferson undertook his investigation of the mound in 1784, a few years after he had begun drafting Notes. Jefferson was hardly the first American to disturb a burial mound; antiquarians had long sought artifacts, while farmers might have been interested only in leveling their fields. But Jefferson was the first American to conduct a scientific archaeological study. As such, his investigation was systematic, it set out to answer clear questions, and its findings were published.
Jefferson began his work by superficially digging in several areas of the mound. In each of these tests, he encountered bones from six inches to three feet below the surface, writing that they were arranged in “utmost confusion,” or as if emptied from a basket and then covered with earth. Modern archaeologists describe this as a bundle secondary burial feature, meaning that Jefferson likely saw the remains of multiple individuals who were reburied from somewhere else. In fact, Jefferson estimated that the mound contained the remains of at least a thousand people. That number is large compared with other burial mounds in North America, but modern studies of similar mounds nearby support the number as reasonable. Jefferson also distinguished between the skulls of adults, children, and infants.
After these initial tests, Jefferson began his more-systematic fieldwork. Although he used the first-person in his writing about the dig, the scale of the excavation suggests that others were involved, presumably slaves from his Monticello plantation. With their help, then, a trench was dug through the mound’s center “wide enough,” Jefferson wrote, “for a man to walk through and examine its sides.” This approach allowed Jefferson to inspect the mound for layers, or strata, a technique that would not enter the archaeological literature until Charles Lyell’s Principles of Geology (1820). The various strata each contained bones covered by dirt, with the bones nearest the surface being the least decayed. Retrospectively, this has suggested that these remains were not as old, although Jefferson did not specifically draw that conclusion.
There are no field notes concerning the dig other than what is published in Notes. There is no evidence that Jefferson collected and kept any of the human remains for study. He made no mention of finding or collecting artifacts amid the human remains, an absence that conforms to the results of a 2003 study conducted by the University of Virginia at the very similar Rapidan Mound, in Orange County, Virginia. Jefferson likely conducted in-field analyses of the human remains and returned them to the trench.
Over the years, the mound deflated. The site, broadly determined, is on private land with its exact location unknown. In 1911, David I. Bushnell Jr. of the Smithsonian Institution searched for the mound but did not find it. In 2000, the possibility of development near the town site associated with the mound’s probable location prompted a blessing ceremony conducted by the Monacan Indian Nation of Amherst County.
Jefferson’s investigation resolved the competing hypotheses concerning the mound’s function, as well as the circumstances of its construction. The presence of children and infant remains, in addition to the remains of adults, and the absence of arrow or bullet wounds suggest that the mound was not the battleground cemetery of warriors. Neither was it, in Jefferson’s words, the “common sepulcher” of a town where persons were interred shortly after dying; rather, the mound’s unusual clustering of disjointed remains led Jefferson to conclude that it “derived both origin and growth” from the customary collection mound was located, and either they or their ancestors likely constructed it. Some archaeologists debate this cultural connection. Because most burial mounds are found west of the Piedmont, these scholars view Jefferson’s Mound and another nearby as representing incursions into the region by Indians from the Blue Ridge Mountains and Shenandoah Valley, Indians who may have had no relation to the Monacans of the seventeenth and eighteenth centuries.
Jefferson concluded his report by noting that the entire complex of thirteen mounds was of “considerable notoriety” to local Indians who, he noted, had conducted a ceremony at the Rivanna River mound sometime about 1754. Although they no longer lived near the mound, Jefferson observed that they knew precisely how to find their way through the woods and directly to the mound. This connection of the mound to the eighteenth-century tribes, made in passing, was significant because it provided some evidence contrary to the “Lost Race” theory.
Popular in Jefferson’s day and for another century after, the Lost Race theory argues that American Indians were not “civilized” enough to have built burial mounds; instead, they must have displaced the actual Mound Builders, who were identified as Welshmen, Norsemen, Phoenicians, Tartars, Chinese, or even Canaanites, the “lost tribes of Israel.” Jefferson did not address the theory directly, and was still given to conjecture on the classical or biblical origins of Virginia Indians in correspondence with John Adams in the 1820s. Excavation of the Ely Mound in Lee County in the 1870s more definitively countered the Lost Race theory.