{"nrhp_refnum":"73001623","name":"Twaddell's Mill and House","other_names":["Great Bend of the Brandywine","Big Bend"],"category":"building","location":{"address":"Rock Hill Rd. S of Chadds Ford","address_restricted":false,"city":"Chadds Ford","county":"Delaware County","state":"PA","lat":39.844329679000055,"lon":-75.57836520546077,"geom_source":"nps_gis"},"listed_date":"1973-03-07","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Architecture"],"significance_levels":["state"],"summary":{"what_it_is":"A stone house at the Great Bend of the Brandywine near Chadds Ford, Delaware County, Pennsylvania, with the remains of an associated mill site and outbuildings. The house is of the stone bank type, built on the site of an older building, and the document dates it to the early nineteenth century.","why_significant":"The nomination argues the house is an outstanding example of architecture, described as a dwelling totally unlike any other in the region, with a mixture of mid-eighteenth century building techniques and more modern ideas of about 1810-20. It also notes the surrounding area's archaeological importance because of Indian settlements, including the reputed Queonomysing village site.","narrative":"Stone bank house at the Great Bend of the Brandywine, two and one-half stories on its north side and three and one-half on the river side, five bays wide on the north and south elevations. Its builder is not documented. The house is generally dated to the early nineteenth century, though it combines mid-eighteenth century building techniques with ideas considered modern around 1810 to 1820. Its basement walls suggest an older building was incorporated into the present structure. Harry Gordon, a British officer who owned the property from 1763 to 1775, is considered the most likely builder, but no papers confirm it. William Twaddell acquired the property in 1779 and held it until his death in 1827, operating a sawmill, an iron forge that later became a powder works, and grist and saw mills. The house was restored after about twenty-five years of vacancy, and its proportions and interior detail are regarded as outstanding.","period_of_significance":"19th Century","architect_builder":null,"architectural_style":null,"criteria":[],"status_note":"Restored by the Weymouths after a period of vacancy of about twenty-five years; the mill is no longer standing and only its foundations and part of its walls remain.","vacant_flag":false,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:31.083168-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/73001623.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/73001623/58e855cf2e-800.webp","url_1600":"https://nationalhistoricalregister.com/media/73001623/58e855cf2e-1600.webp","licence":"CC BY-SA 3.0","author":"JERRYE &amp; ROY KLOTZ MD","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:TWADDELL%27S_MILL_AND_HOUSE.jpg\" rel=\"noopener\">JERRYE &amp;amp; ROY KLOTZ MD</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:TWADDELL%27S_MILL_AND_HOUSE.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/71994955","wikipedia":"https://en.wikipedia.org/wiki/Twaddell%27s_Mill_and_House","wikidata":"https://www.wikidata.org/wiki/Q7857399"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/delaware-county/twaddells-mill-and-house-73001623/"}