Harmony's Mennonites built their stone meetinghouse in 1825 near their hilltop cemetery just north of town. The brick annex was an early addition. Services were always conducted in German. The congregation dwindled as the 19th century progressed, and the last regular services to be held in the meetinghouse occured in 1902. It is the oldest Mennonite meetinghouse west of the Alleghenies, and the most original early Mennonite meetinghouse in the nation.