Extremely Rare Three-Gallon Stoneware Jug with Large Cobalt Floral Decoration, Incised "John S. Clemmer / Mogadore Summit Co / Ohio", mid 19th century, ovoid jug with tapered spout, decorated with a large brushed tulip motif with dashed blossom, emanating from a leafy stem. Incised at the shoulder with the inscription "John S. Clemmer / Mogadore Summit Co. / Ohio" above an incised pointing hand. This jug was made and signed by documented abolitionist and potter, John S. Clemmer (1825-1875). Clemmer, along with his wife, Maria, operated an Underground Railroad safehouse for slaves of the Ohio River Valley. In 1861, Clemmer joined the Ninth Ohio Volunteers and suffered a serious injury on June 9, 1862 at the Battle of Port Republic, Virginia. We are aware of no other American stoneware potters who have been documented as having a significant role in the Underground Railroad. This jug combines classic Ohio form and decoration with outstanding historical significance. Literature: Mary Ellen Snodgrass, The Underground Railroad: An Encyclopedia of People, Places, and Operations, (Routledge, 2015). Provenance: Crocker Farm, Inc., July 16, 2016, lot 342. Excellent, essentially as-made condition with minor wear to base of handle. H 15 3/4".