{"nrhp_refnum":"76001679","name":"Acheson, Edward G., House","other_names":[],"category":"building","location":{"address":"908 Main St.","address_restricted":false,"city":"Monongahela","county":"Washington County","state":"PA","lat":40.20552506350006,"lon":-79.9342350637053,"geom_source":"nps_gis"},"listed_date":"1976-05-11","is_nhl":true,"nhl_designated_date":"1976-05-11","areas_of_significance":["Invention"],"significance_levels":["national"],"summary":{"what_it_is":"A detached 2-1/2 story brick house at 908 Main Street in Monongahela, Washington County, Pennsylvania. The date of construction, architect and builder are unknown; it was probably built in the 1870s.","why_significant":"The nomination argues the house is significant because Edward Goodrich Acheson invented carborundum (silicon carbide) while living there from 1890 to 1895, probably in a summer kitchen converted to a laboratory. The architecture is described as vernacular and of no architectural significance, so the listing rests on the invention and its association with Acheson.","narrative":"A detached 2-1/2 story brick house at 908 Main Street in Monongahela, Pennsylvania, probably built in the 1870s. Its builder and architect are not known, and the house is described as a plain vernacular domestic building with an asymmetrical plan, a front double bay, a side projection and a two-story service wing. Edward Goodrich Acheson lived here from 1890 to 1895. In March 1891 he conducted experiments in Monongahela that led to carborundum, or silicon carbide, an artificial abrasive harder than any substance previously known. Local tradition and the owner's account place the discovery in a summer kitchen that Acheson converted into a small laboratory, though the house itself is the documented location. Acheson later developed graphite products from the same thermochemical process and held nearly 70 patents. He received the Rumford Premium in 1908 and the Perkins Medal in 1910. The house is listed for its association with this invention and with Acheson's career as an inventor.","period_of_significance":"1890-1895","architect_builder":null,"architectural_style":null,"criteria":[],"status_note":"The present owner's account and the form describe the house as unaltered apart from removal of a frame wash house and interior kitchen and laundry changes; the form lists its condition as excellent.","vacant_flag":false,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:31.01537-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/76001679_NHL.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/76001679/edf12f3147-800.webp","url_1600":"https://nationalhistoricalregister.com/media/76001679/edf12f3147-1600.webp","licence":"Public domain","author":"Nyttend","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Edward_G._Acheson_House.jpg\" rel=\"noopener\">Nyttend</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Edward_G._Acheson_House.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71994247","wikipedia":"https://en.wikipedia.org/wiki/Edward_G._Acheson_House","wikidata":"https://www.wikidata.org/wiki/Q5343028"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/washington-county/acheson-edward-g-house-76001679/"}