{"nrhp_refnum":"72001103","name":"Oakdale","other_names":["Mendenhall,Isaac,Estate"],"category":"building","location":{"address":"Hillendale Rd., Pennsbury Township","address_restricted":false,"city":"Chadds Ford","county":"Chester County","state":"PA","lat":39.86097657100004,"lon":-75.62126811299999,"geom_source":"nps_gis"},"listed_date":"1972-01-13","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Black","Architecture","Social History"],"significance_levels":["national"],"summary":{"what_it_is":"Oakdale is a farmhouse and former carriage house complex at Oakdale Farm in Chadds Ford, Chester County, Pennsylvania, on the western banks of the Brandywine Creek. The main house was built in 1840 by Isaac Mendenhall, with an eighteenth-century portion and later alterations.","why_significant":"The nomination argues the property is significant for its association with Isaac and Dinah Mendenhall, abolitionists who sheltered fugitives on the Underground Railroad, and as a good example of the simple, spacious homes of prosperous southeastern Pennsylvania Friends. It also notes a concealed hideaway room in the carriage house used by fleeing slaves.","narrative":"Built in 1840 by Isaac Mendenhall on Oakdale Farm beside the Brandywine Creek in Chester County, the farmhouse follows the proportions and floor plan of the nearby Springdale house, which Ellwood Mendenhall built in 1836, with changes such as a south bay window and a raised roof to form a third story. The Mendenhall family held the farm from 1684 into the mid 1920s. Isaac and Dinah Mendenhall were leading abolitionists who helped found the Society of Progressive Friends at Longwood in 1853. Their farm was the first stop north of the Delaware line on the Underground Railroad, and they often sheltered fugitives from the South. A square hideaway room in the old carriage house, reached through the loft and ventilated through gaps in the stonework, was used to conceal escaping slaves. The house is regarded as a good example of the plain but roomy homes of prosperous Quaker families in southeastern Pennsylvania.","period_of_significance":"1840","architect_builder":null,"architectural_style":null,"criteria":[],"status_note":"The present exterior is described as much as it was, with twentieth-century changes including removal of a north porch in the 1930s and addition of a screen porch by the present owners in the 1950s.","vacant_flag":null,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:29.872484-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/72001103.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/72001103/e7647aa244-800.webp","url_1600":"https://nationalhistoricalregister.com/media/72001103/e7647aa244-1600.webp","licence":"CC0","author":"Smallbones","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Oakdale_Chesco.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:Oakdale_Chesco.jpg"},"district":{"nrhp_refnum":"100001635","name":"Twin Bridges Rural Historic District","url":"https://nationalhistoricalregister.com/districts/pennsylvania/twin-bridges-rural-historic-district-100001635/"},"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71994945","wikipedia":"https://en.wikipedia.org/wiki/Oakdale_(Pennsbury_Township,_Pennsylvania)","wikidata":"https://www.wikidata.org/wiki/Q7073794"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/chester-county/oakdale-72001103/"}