Fort Jefferson (Ohio)
| Fort Jefferson Site | |
| Southern side of the hill on which the fort sat | |
| Location | State Route 121 in Neave Township, Darke County, Ohio | 
|---|---|
| Coordinates | 40°1′32″N 84°39′24″W / 40.02556°N 84.65667°W | 
| Area | 6.5 acres (2.6 ha) | 
| Built | 1791 | 
| NRHP reference No. | 70000488 | 
| Added to NRHP | November 10, 1970 | 
Fort Jefferson was a fortification erected by soldiers of the United States Army in October 1791 during the Northwest Indian War. Built to support a military campaign, it saw several years of active fighting. Today, the fort site is a historic site.