Fort Ancient (33 WA 2) is a Native American earthworks complex located in Washington Township, Warren County, Ohio, along the eastern shore of the Little Miami River about seven miles (11 km) southeast of Lebanon on State Route 350. The site is the largest prehistoric hilltop enclosure in the United States with three and one-half miles (18,000 ft) of walls in a complex. Built by the Hopewell culture, who lived in the area from the 200 BC to AD 400, the site is situated on a wooded bluff above the Little Miami. It is the namesake of a culture known as Fort Ancient who lived near the complex long after it was constructed.
Maintained as a state historical park, the site was designated a National Historic Landmark for its significance. The State of Ohio purchased the land and made it Ohio's first state park in 1891. In addition, this is part of the Hopewell Ceremonial Earthworks, one of 14 sites nominated in January 2008 by the U.S. Department of the Interior for potential submission by the United States to the UNESCO World Heritage List. It was officially designated a World Heritage Site on September 2023 together with the earthworks at Hopewell Culture National Historical Park and the Newark Earthworks.
Construction
The Fort Ancient earthworks were built in at least three stages over an estimated 400-year period. The shoulder blades of deer, split elk antlers, clam shell hoes, and digging sticks were used to loosen the dirt, and baskets holding 35 to 40 pounds were used to carry and distribute the soils in building the earthworks. Archaeologists estimate the total volume of earth in the walls at .
Archaeological Research
In 1809 the Philadelphia Port Folio published the first map and description of Fort Ancient. The accounts of the site by Atwater and Warden several years later are nearly identical to the 1809 report and map. The site was visited and surveyed in by John Locke in 1843. In Edwin Hamilton Davis and Ephraim George Squier's Ancient Monuments of the Mississippi Valley, they described Fort Ancient as "one of the most extensive, if not the most extensive, work...in the entire West", regarding its size. Warren K. Moorehead conducted some of the initial excavations at Fort Ancient in 1887 and published his research in 1891 in the book Fort Ancient: Great Prehistoric Warren County Ohio. Additional research was conducted by William C. Mills in 1908 and Richard Morgan and Holmes Ellis in 1939-1940.
More contemporary research includes the following:
From 1982 until her untimely death in 1991, Patricia Essenpreis conducted a series of excavations that included the re-excavation and examination of embankment wall cuts conducted by Richard Morgan. These excavations demonstrated that the embankment walls were built in multiple stages and that post structures were documented at the base of the walls. She also examined the Gateway 13 exterior spur where she found evidence of bladelet manufacturing. Her final project involved the excavation of a pavement and structure on the exterior of the earthworks near the Twin Mound complex. Here, she documented a three-level limestone pavement with household or domestic activity at the lowest level. From 1987 through 2006, Robert Connolly collaborated with and then continued the research projects initiated by Patricia Essenpreis. His initial work involved taking Essenpreis's "canons of construction" to develop an "architectural grammar" of earthwork elements, demonstrating their intentional and precise placement throughout the Fort Ancient complex. In 1995 and 1996 Connolly directed the investigation of embankment walls and a large interior space of the North Fort of the earthwork in advance of a new museum construction. The embankment wall excavation confirmed Essenpreis' conclusion of multiple construction levels, but added a level of complexity in alternate basket loads of different soils in the construction, many features below the embankment wall, and a three-level limestone pavement on the exterior of the wall that contained a cache of burnt animal bones. Excavation in the North Fort interior space revealed the presence of 10 habitation structures. Beginning in 2006, Robert Riordan conducted excavations in the North Fort of the earthwork complex that revealed a complex series of posts and activity areas, some with intense burning. Riordan named the Moorehead Circle after the archaeologist who conducted early excavations at the site.