{"nrhp_refnum":"76001262","name":"U.S. Customhouse","other_names":[],"category":"building","location":{"address":"W. Oneida St. between 1st and 2nd Sts.","address_restricted":false,"city":"Oswego","county":"Oswego County","state":"NY","lat":43.45482153800003,"lon":-76.51089595999997,"geom_source":"nps_gis"},"listed_date":"1976-11-21","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Commerce","Politics/Government","Architecture"],"significance_levels":["state"],"summary":{"what_it_is":"A three-story, flat-roofed limestone customhouse on West Oneida Street in Oswego, New York, completed in 1858 and designed by Ammi B. Young. Two-story wings were added in 1935.","why_significant":"The customhouse played a significant role in the development of the port of Oswego and maritime commerce on Lake Ontario, regulating traffic in salt, grain, and timber between Oswego, Canada, and the West. It is an early \"fireproof\" building with a cast-iron structural system by Ammi B. Young, Supervisory Architect of the U.S. Treasury. It is considered among the finest surviving examples of his work.","narrative":"Built in 1858 on West Oneida Street, one block west of the Oswego River, this limestone customhouse served the port of Oswego on Lake Ontario. It has three stories, a raised limestone basement, rusticated first-story walls, round-arched windows, and a projecting arcaded entrance pavilion on the north side. Two-story wings matching the original walls were added in 1935. Ammi B. Young, then Supervisory Architect of the U.S. Treasury, designed it with cast-iron columns and staircases as a fireproofing measure. The building is regarded as one of the finest surviving examples of his work and retains much of its original fabric. The customhouse regulated trade in salt, grain, and timber between Oswego, Canada, and the expanding West. Oswego's shipping importance declined after the Civil War but later revived with the St. Lawrence Seaway. The building continues to serve as the city's main post office and federal building.","period_of_significance":"1858","architect_builder":"Ammi B. Young (1798-1874)","architectural_style":"Neo-classical; Italianate, Renaissance Revival north Italian mode","criteria":[],"status_note":"Occupied and still in use as Oswego's main post office and federal office space; the form lists condition as altered, with an elevator and loading dock added in the twentieth century and the interior partitioned.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:50:39.294296-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_NY/76001262.pdf"},"photo":null,"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/75320893","wikipedia":"https://en.wikipedia.org/wiki/United_States_Customhouse_(Oswego,_New_York)","wikidata":"https://www.wikidata.org/wiki/Q7889710"},"indexable":true,"url":"https://nationalhistoricalregister.com/new-york/oswego-county/u-s-customhouse-76001262/"}