{"nrhp_refnum":"84003105","name":"Allegheny Aqueduct","other_names":["Gibraltar Aqueduct"],"category":"structure","location":{"address":"PA 724 and Allegheny Creek","address_restricted":false,"city":"Gibraltar","county":"Berks County","state":"PA","lat":40.286066127000026,"lon":-75.88655760799998,"geom_source":"nps_gis"},"listed_date":"1984-02-23","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Commerce","Engineering"],"significance_levels":["state"],"summary":{"what_it_is":"A stone aqueduct carrying Schuylkill Navigation Company canal boats across Allegheny Creek at the western edge of Gibraltar in Robeson Township, Berks County, Pennsylvania. Built in 1824, it is also referred to as the Gibraltar Aqueduct.","why_significant":"The nomination argues the aqueduct embodies the evolution of early canal technology and engineering in Pennsylvania and links the canal system to regional economic growth in commerce, agriculture, and coal mining. It is described as the second longest aqueduct in the Schuylkill Canal system when built and as the only intact structure of its type from that system. Its unspoiled setting adds to its rarity.","narrative":"Spanning Allegheny Creek at the western edge of Gibraltar in Robeson Township, Berks County, this stone aqueduct carried Schuylkill Navigation Company canal boats across the stream. Built in 1824 by contractors Samuel Pettitt and Ehner Kimber under engineer Ephraim Beecher, it has five stone arches with a 112-foot span, faced mainly in brownstone with limestone on the towpath wall. The canal opened in July 1824 as part of the Girard Canal, financed by Stephen Girard and linking the coal regions, farmlands and Philadelphia. Coal, wheat, flour and iron passed over the structure, and system-wide shipments peaked in 1859 at 1,700,000 long tons. Repairs in 1827 and 1828 used brick in the vaults, and the canal was later used for a water supply serving the Birdsboro steel works. It is regarded as the only intact aqueduct of its type on the Schuylkill Canal, most others having been demolished or collapsed. The surrounding site remains largely undeveloped.","period_of_significance":"1800-1899","architect_builder":"S. Pettitt and E. Kimber","architectural_style":null,"criteria":[],"status_note":"Overall in reasonably good condition, with a collapsed section of the central arch vault and deterioration from vegetation; the canal was drained in 1967 for Route 724.","vacant_flag":null,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:32.606402-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/84003105.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/84003105/fc659e6043-800.webp","url_1600":"https://nationalhistoricalregister.com/media/84003105/fc659e6043-1600.webp","licence":"CC BY-SA 2.0","author":"Doug Kerr from Albany, NY, United States","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Allegheny_Aqueduct_-_Gibraltar,_Pennsylvania_(5655164775).jpg\" rel=\"noopener\">Doug Kerr from Albany, NY, United States</a>, <a href=\"https://creativecommons.org/licenses/by-sa/2.0\" rel=\"license noopener\">CC BY-SA 2.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Allegheny_Aqueduct_-_Gibraltar,_Pennsylvania_(5655164775).jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71995663","wikipedia":"https://en.wikipedia.org/wiki/Allegheny_Aqueduct","wikidata":"https://www.wikidata.org/wiki/Q4731277"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/berks-county/allegheny-aqueduct-84003105/"}