Fort Barnesville is believed to have been built by the Union army in early 1863 to observe troop movement along the Belleview Trail. The fort was discovered by Dan Massie while hunting in the 1950s. In 1995, Gerald Angel, assisted by John Bradbury, Jerry Ponder and Joe Huett, researched and authenticated the fort. It was placed on the National Register of Historic Places on July 1, 1998.