{"nrhp_refnum":"88000820","name":"Fortieth Street Bridge","other_names":["Washington Crossing Bridge"],"category":"structure","location":{"address":"Fortieth St. over Allegheny River","address_restricted":false,"city":"Millvale","county":"Allegheny County","state":"PA","lat":40.47355254900003,"lon":-79.96969574899998,"geom_source":"nps_gis"},"listed_date":"1988-06-22","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering"],"significance_levels":["state"],"summary":{"what_it_is":"A bridge carrying vehicular traffic over the Allegheny River and railroad tracks between Pittsburgh and Millvale in Allegheny County, Pennsylvania, listed in the Highway Bridges Owned by the Commonwealth of Pennsylvania multiple resource area. It is also known as the Washington Crossing Bridge.","why_significant":"The nomination argues the bridge is significant under engineering, as the only long-span deck arch bridge included in the nomination. It commemorates George Washington's crossing of the river on December 24, 1753, and its railing plaques depicting the original 13 colonies support its historic theme. The Allegheny County engineers who reviewed its plans, V.R. Covell and J.G. Chalfont, are also noted, with Covell later serving as Chief Engineer for Pittsburgh's Bureau of Bridges.","narrative":"Spanning the Allegheny River and railroad tracks between Pittsburgh and Millvale, this bridge opened to traffic on December 24, 1924. Its main span is a riveted steel deck arch about 308 feet long, and the full crossing measures 2,366 feet across fifteen spans. Massive concrete piers and abutments support the steel structure. Abstract classical detailing and railing plaques showing the original 13 colonies give the bridge its historic character. The bridge was designed between 1919 and 1924 under Allegheny County engineers J.G. Chalfont and V.R. Covell, and it is significant for engineering. Its opening date coincides with the anniversary of George Washington's 1753 crossing of the river, which the bridge commemorates. Covell later became Chief Engineer for Pittsburgh's Bureau of Bridges and designed several innovative bridges in the city. The bridge was reconstructed in 1969.","period_of_significance":"1919-1924","architect_builder":"Benno Tansson (designer/engineer); H. V. Converse & Co.; McClintic-Marshall Co. (builder/contractor)","architectural_style":"Abstract classical detailing","criteria":[],"status_note":"Open to traffic since 1924; major reconstruction in 1969.","vacant_flag":false,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:36.730028-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/88000820.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/88000820/0cd3d7bfa6-800.webp","url_1600":"https://nationalhistoricalregister.com/media/88000820/0cd3d7bfa6-1600.webp","licence":"CC BY-SA 4.0","author":"Lee Paxton","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:FortiethStreetBridge.jpg\" rel=\"noopener\">Lee Paxton</a>, <a href=\"https://creativecommons.org/licenses/by-sa/4.0\" rel=\"license noopener\">CC BY-SA 4.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:FortiethStreetBridge.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71992218","wikipedia":"https://en.wikipedia.org/wiki/Washington_Crossing_Bridge_(Pittsburgh)","wikidata":"https://www.wikidata.org/wiki/Q7971800"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/allegheny-county/fortieth-street-bridge-88000820/"}