{"nrhp_refnum":"09001213","name":"Chandler Mill Bridge","other_names":["Chandlers Mill Bridge","Chester County Bridge No. 236"],"category":"structure","location":{"address":"Kennett Township","address_restricted":false,"city":"Kennett","county":"Chester County","state":"PA","lat":39.81335239200007,"lon":-75.71310366599994,"geom_source":"nps_gis"},"listed_date":"2010-01-11","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Transportation","Engineering"],"significance_levels":["local"],"summary":{"what_it_is":"A single-span, built-up steel plate through girder road bridge carrying Chandler Mill Road over the West Branch of Red Clay Creek in Kennett Township, Chester County, Pennsylvania. It was built in 1910 by the County of Chester as County Bridge No. 236.","why_significant":"The nomination argues the bridge is locally significant under transportation and engineering for documenting the county's assumption of local bridge responsibilities from townships. It is also presented as an example of the through girder plate girder type, built across Chester County from the 1890s to the 1930s as an inexpensive, practical road bridge with no aesthetic considerations.","narrative":"Built in 1910 across the West Branch of Red Clay Creek in Kennett Township, Chester County, Chandler Mill Bridge is a 47-foot single-span, built-up steel plate through girder bridge with a concrete deck, carried on hand-laid fieldstone abutments and wingwalls capped with slate. The county built it to replace a township bridge on Chandler Mill Road that had flooded because it was set too low and was too narrow. It was erected by private contractor George Dole under County Engineer Nathan R. Rambo. The structure is considered important as a surviving example of a bridge type common in Chester County from the 1890s to the 1930s, when steel through girders were the favored form for county road bridges. Its plain, practical design reflects municipalities seeking durable, inexpensive crossings. The bridge also records the shift in responsibility for local roads from townships to the county in the early twentieth century. A stone plaque on the north wingwall lists the county commissioners and officials of the period.","period_of_significance":"1910","architect_builder":"Rambo, Nathan R., P.E. (planner/surveyor per amendments); Dole, George (contractor)","architectural_style":null,"criteria":["A","C"],"status_note":"Amendments state the 2009 inspection rated the bridge in overall poor condition, though the main description calls it in fair condition; the deck was blacktopped after 1997.","vacant_flag":false,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:10:27.179122-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/09001213.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/09001213/edfd24a71e-800.webp","url_1600":"https://nationalhistoricalregister.com/media/09001213/edfd24a71e-1600.webp","licence":"Public domain","author":"Smallbones","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Chandler_Mill_Bridge.JPG\" rel=\"noopener\">Smallbones</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Chandler_Mill_Bridge.JPG"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71996024","wikipedia":"https://en.wikipedia.org/wiki/Chandler_Mill_Bridge","wikidata":"https://www.wikidata.org/wiki/Q5071177"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/chester-county/chandler-mill-bridge-09001213/"}