{"nrhp_refnum":"84003447","name":"Spring Grove Forge Mansion","other_names":[],"category":"building","location":{"address":"Spring Grove Rd.","address_restricted":false,"city":"East Earl","county":"Lancaster County","state":"PA","lat":40.14491042800006,"lon":-76.02100777399994,"geom_source":"nps_gis"},"listed_date":"1984-07-11","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Industry","Architecture"],"significance_levels":["local"],"summary":{"what_it_is":"Spring Grove Forge Mansion is a large L-shaped two-story stone house overlooking the Conestoga River in East Earl Township, Lancaster County, Pennsylvania. Its main block was built in three stages between 1789 and 1830 for the ironmaster Cyrus Jacobs, and it incorporates an older west kitchen wing associated with Thomas Edwards.","why_significant":"The nomination argues the house is significant for its architecture and as a monument to Lancaster County's iron industry. It is described as the most intact of at least six houses built for Cyrus Jacobs, and as the only ironmaster's mansion in the county showing three architectural styles in one building. Its gouge carved piazza is presented as a unique survival with no larger or finer example known in the county.","narrative":"Built of local stone on a rise above the Conestoga River in East Earl Township, Lancaster County, Spring Grove Forge Mansion took shape in three stages between 1789 and 1830 for the ironmaster Cyrus Jacobs. The L-shaped two-story house has a six bay south facade with a gouge carved piazza, believed to date from about 1805 to 1815, that carries carved mouldings and fretwork friezes. Its interior holds plasterwork ceiling medallions, several marble mantels from about 1820 to 1830, and a Federal mantel of about 1810 with bamboo turned engaged columns. The northeast second-floor chamber keeps its original Georgian woodwork from about 1790, including built-in drawers beneath the cupboards. The west kitchen wing is believed to predate 1764, when Thomas Edwards died. The house is regarded as the most intact of Jacobs' houses and a record of the county's wealthy iron manufacturing.","period_of_significance":"Pre 1789 - c. 1830","architect_builder":null,"architectural_style":"Georgian, Federal and Classical Revival","criteria":[],"status_note":"Remarkably intact to its state at the time of Cyrus Jacobs' death in 1830; the sun porch is a c. 1930 addition.","vacant_flag":null,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:33.12227-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/84003447.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/84003447/7b1085408c-800.webp","url_1600":"https://nationalhistoricalregister.com/media/84003447/7b1085408c-1600.webp","licence":"CC BY-SA 3.0","author":"Smallbones","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Spring_Grove_Forge_Mansion.JPG\" rel=\"noopener\">Smallbones</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:Spring_Grove_Forge_Mansion.JPG"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71995331","wikipedia":"https://en.wikipedia.org/wiki/Spring_Grove_Forge_Mansion","wikidata":"https://www.wikidata.org/wiki/Q7580539"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/lancaster-county/spring-grove-forge-mansion-84003447/"}