{"nrhp_refnum":"91001141","name":"Mary Ann Furnace Historic District","other_names":["Trexler's Furnace"],"category":"district","location":{"address":"Centennial Rd. SE of Longswamp, Longswamp Township","address_restricted":false,"city":"Longswamp","county":"Berks County","state":"PA","lat":40.48472931900005,"lon":-75.64808542299994,"geom_source":"nps_gis"},"listed_date":"1991-09-06","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Industry","Architecture"],"significance_levels":["state"],"summary":{"what_it_is":"An iron plantation in Longswamp Township, Berks County, Pennsylvania, centred on the Mary Ann Furnace, built in 1789 by Jacob Lesher along the Little Lehigh Creek. The historic district includes the collapsed furnace stack, a manager's house and office, a bank barn, a blacksmith shop, a charcoal house, a stone dam and a worker's house.","why_significant":"The district is nominated under Criterion A for its association with the early iron industry in eastern Pennsylvania and as a good example of a modest iron plantation. It is also nominated under Criterion C for its architecture, particularly the Federal-style entrance frontispieces of the manager's house and the bank barn. The blacksmith shop is described as rarely found in such original condition.","narrative":"Mary Ann Furnace, an iron plantation in Longswamp Township in Berks County, Pennsylvania, was erected in 1789 by Jacob Lesher beside the Little Lehigh Creek. Its operation passed to his son-in-law Reuben Trexler in 1808 and then to Trexler's son Horatio in 1837, who ran it until the furnace closed in 1869. The surviving complex includes the collapsed furnace stack, a stone manager's house with Federal-style entrance frontispieces, an office building, a bank barn, a dated 1854 blacksmith shop, a charcoal house, a stone dam and a worker's house. Reuben Trexler is credited with making the first anthracite stoves in Pennsylvania around 1820, and the furnace later cast the Lehigh Coal Stove until 1857. The district is valued for its early role in the iron industry of eastern Pennsylvania and for the integrity of its buildings, which together show the layout of the original plantation.","period_of_significance":"1789-1869","architect_builder":null,"architectural_style":"other: 99 iron furnace","criteria":["A","C"],"status_note":"The furnace closed in 1869 and the property was afterwards converted to agricultural use; it is still being farmed.","vacant_flag":null,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:37.752415-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/91001141.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/91001141/49c47fd9f7-800.webp","url_1600":"https://nationalhistoricalregister.com/media/91001141/49c47fd9f7-1600.webp","licence":"CC BY-SA 3.0","author":"PattiParker","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Mary_Ann_Furnace_2.JPG\" rel=\"noopener\">PattiParker</a>, <a href=\"https://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:Mary_Ann_Furnace_2.JPG"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71992402","wikipedia":"https://en.wikipedia.org/wiki/Mary_Ann_Furnace_Historic_District","wikidata":"https://www.wikidata.org/wiki/Q6778873"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/berks-county/mary-ann-furnace-historic-district-91001141/"}