{"nrhp_refnum":"100008901","name":"Walnut Street Bridge","other_names":["Wagner’s Mill Bridge","County Bridge No. 14"],"category":"structure","location":{"address":"200 ft. west of the intersection of Walnut St. and the Saucon Valley Rail Tr.","address_restricted":false,"city":"Hellertown","county":"Northampton County","state":"PA","lat":40.57253700000007,"lon":-75.34363399999995,"geom_source":"nps_gis"},"listed_date":"2023-05-08","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering"],"significance_levels":["national"],"summary":{"what_it_is":"A nearly one-mile-long wrought iron truss bridge over the Susquehanna River, divided by City Island, with seven spans on the west side and four spans of 175 feet and three of 240 feet on the east side. It was completed in 1890 in the Hellertown area of Northampton County, Pennsylvania.","why_significant":"The bridge is built with the Phoenix Column, a rolled wrought iron construction method patented by Samuel Reeves, which was among the most popular bridge types in the United States from about 1867 to the late nineteenth century. It is regarded as one of the last surviving and best-preserved multispan Phoenix bridges in the East, and one of the last large bridges made of wrought iron.","narrative":"Spanning the Susquehanna River in Northampton County, the Walnut Street Bridge was completed in 1890 and is almost a mile long, divided by City Island near the middle of the river. Its superstructure was fabricated by the Phoenix Bridge Company in Phoenixville, Pennsylvania, and assembled on site by Dean & Westbrook of New York. The main supporting members are built of rolled semicircular wrought iron sections riveted together, a method known as the Phoenix Column, which allowed bridges of almost any size to be built from standardized, prefabricated parts. The spans rest on dressed stone piers, and the longer 240-foot spans cross the active channel and were designed to allow passage for logging operations and coal barges, both once common on the Susquehanna. Few large wrought iron bridges of this type remain, and this one is considered among the best surviving examples of the Phoenix Column in the East.","period_of_significance":"1889-1890","architect_builder":"Phoenix Bridge Co. (fabrication); Dean & Westbrook (assembly)","architectural_style":null,"criteria":["C"],"status_note":"Otherwise sound; the bridge needs repainting and some pier repair, and handles about 8,000 cars daily. Steel lattice flooring replaced the original wooden planks and steel guard rails were welded to the sides.","vacant_flag":false,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:13:40.937563-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/72001115.pdf"},"photo":null,"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":null,"wikipedia":null,"wikidata":null},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/northampton-county/walnut-street-bridge-100008901/"}