{"nrhp_refnum":"66000671","name":"Cornwall Iron Furnace","other_names":[],"category":"district","location":{"address":"Rexmont Rd. and Boyd St.","address_restricted":false,"city":"Cornwall","county":"Lebanon County","state":"PA","lat":40.270994548856706,"lon":-76.40698546876379,"geom_source":"nps_gis"},"listed_date":"1966-11-13","is_nhl":true,"nhl_designated_date":"1966-11-03","areas_of_significance":["Industry"],"significance_levels":["national"],"summary":{"what_it_is":"Cornwall Furnace is a charcoal iron-making complex in Cornwall Borough, Lebanon County, Pennsylvania, comprising the furnace and its stack, associated service buildings, the ironmaster's mansion known as Cornwall Manor, a stone miners' village, and the adjacent open-pit Cornwall ore mine. The furnace was begun in 1739 and completed in 1742 by Peter Grubb.","why_significant":"The nomination argues the complex exemplifies the iron-making works that produced most of America's iron before the Civil War, and that the furnace is probably the best-preserved charcoal furnace in the United States. It also cites the Cornwall ore deposit as the largest known iron ore deposit in the country before the Lake Superior fields were developed, and the furnace's role in supplying cannon and shot during the American Revolution.","narrative":"Cornwall Furnace is a charcoal iron-making complex in Lebanon County, Pennsylvania, built by Peter Grubb between 1739 and 1742 with a sandstone stack about 30 feet high. It includes the furnace, casting house, charcoal house, and water-wheel and steam-engine rooms, along with service buildings, an ironmaster's mansion, a miners' village of stone double houses, and the adjacent open-pit ore mine on Big, Middle, and Grassy Hills. The furnace produced pig iron from 1742 to 1883 and, during the Revolution, cast cannon and shot for the navy. Its ore deposit was among the largest in the country before the Lake Superior fields were developed. The complex is regarded as one of the best-preserved charcoal furnaces in the United States and illustrates how early American iron plantations were organized, with farmland, woodcutting, and worker housing supporting the furnace. Coleman family ownership from the late 1700s shaped the mansion and the later modernization of 1856-1857.","period_of_significance":"1742-1883","architect_builder":null,"architectural_style":null,"criteria":[],"status_note":"The furnace complex is maintained by the Commonwealth of Pennsylvania in excellent condition; the Manor is owned by the United Methodist Church and the miners' village houses continue to be inhabited.","vacant_flag":false,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:30.168101-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/66000671_NHL.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/66000671/173ad74a59-800.webp","url_1600":"https://nationalhistoricalregister.com/media/66000671/173ad74a59-1600.webp","licence":"CC BY-SA 3.0","author":"Wherring at en.wikipedia","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:CornwallFurnacePA.jpg\" rel=\"noopener\">Wherring at en.wikipedia</a>, <a href=\"http://creativecommons.org/licenses/by-sa/3.0/\" rel=\"license noopener\">CC BY-SA 3.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:CornwallFurnacePA.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71994173","wikipedia":"https://en.wikipedia.org/wiki/Cornwall_Iron_Furnace","wikidata":"https://www.wikidata.org/wiki/Q15211708"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/lebanon-county/cornwall-iron-furnace-66000671/"}