The Union Church was built in 1825 and is the oldest public building in the town of Mechanicsburg. This church never had a regular congregation or pastor, but various congregations from the town used the building for meetings until they could afford their own building.
Historic Marker: An on-site marker reads: "Oldest public building in Mechanicsburg. Built in 1825 on land given by Martin Rupp. As provided in the charter, it has been used by many religious sects on payment of small fee."