{"nrhp_refnum":"89001818","name":"Monroe Furnace","other_names":[],"category":"district","location":{"address":"Jct. PA 26 and Legislative Rt. 31076, 6 mi. NW of McAlevys Fort","address_restricted":false,"city":"McAlevys Fort","county":"Huntingdon County","state":"PA","lat":40.695382117000065,"lon":-77.89465731201847,"geom_source":"nps_gis"},"listed_date":"1989-11-13","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Industry","Historic - Non-Aboriginal"],"significance_levels":["local"],"summary":{"what_it_is":"Monroe Furnace is a historic district in McAlevys Fort, Huntingdon County, Pennsylvania, consisting of the remains of a charcoal iron blast furnace stack, its surroundings, and foundation remains of workers' housing. It is classed as an iron plantation.","why_significant":"The district is argued to represent the charcoal iron industry in Huntingdon County under criterion A. The foundation remains of workers' housing are said to hold information on worker housing size, spatial arrangement, and the development of iron plantations under criterion D. The stack and slag may also clarify the short, sporadic nature of production at the site.","narrative":"Monroe Furnace is a charcoal iron plantation in McAlevys Fort, Huntingdon County, Pennsylvania, where a blast furnace was established in 1846-47 by General James Irvin, a prominent Centre County ironmaster. The furnace stack is about 20 feet high and 30 feet square at the base, built of cut native sandstone with large corner stones. Its three arches include a 14-foot casting arch on the east and a 12-foot tuyere arch on the north. Foundations of fourteen workers' houses lie along the road to Mooresville. In 1850 Irvin employed 50 men and produced 958 tons of pig iron. Economic depression in the mid-1850s forced his retirement in 1857. George W. Johnston & Co. of Boalsburg later bought the works around 1855 and ran a stove foundry there. The site is regarded as significant for its evidence of a short-lived, sporadic iron operation and the layout of its workers' housing.","period_of_significance":"1847-1864","architect_builder":null,"architectural_style":null,"criteria":["A","D"],"status_note":"The furnace stack is overgrown and partly collapsed at the northeast corner, and its casting area has been obscured by highway drainage cinders.","vacant_flag":null,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:37.034359-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/89001818.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/89001818/478ff19edb-800.webp","url_1600":"https://nationalhistoricalregister.com/media/89001818/478ff19edb-1600.webp","licence":"CC0","author":"Smallbones","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Monroe_Furnace_ruins.jpg\" rel=\"noopener\">Smallbones</a>, <a href=\"http://creativecommons.org/publicdomain/zero/1.0/deed.en\" rel=\"license noopener\">CC0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Monroe_Furnace_ruins.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71993049","wikipedia":"https://en.wikipedia.org/wiki/Monroe_Furnace","wikidata":"https://www.wikidata.org/wiki/Q6902199"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/huntingdon-county/monroe-furnace-89001818/"}