{"nrhp_refnum":"83000800","name":"Flentje, Ernst, House","other_names":[],"category":"building","location":{"address":"129 Magazine St.","address_restricted":false,"city":"Cambridge","county":"Middlesex County","state":"MA","lat":42.35907141400003,"lon":-71.11134089299998,"geom_source":"nps_gis"},"listed_date":"1983-06-30","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Architecture"],"significance_levels":["local"],"summary":{"what_it_is":"A wooden residence at 129 Magazine Street in Cambridgeport, Cambridge, Massachusetts, built in 1866 as a Mansard-style single-family home and remodelled in 1900 into an elaborate Colonial Revival three-decker apartment building.","why_significant":"The nomination argues the house is the stylistic epitome of the three-decker type in Cambridge, described by a survey director as the most exaggeratedly elaborate in Cambridgeport. Its conversion from a mansion to an opulent three-decker reflects social change in Cambridgeport around 1900, when the three-decker gained acceptance as middle-class housing through architectural elaboration.","narrative":"Built in 1866 at 129 Magazine Street in Cambridgeport, this wooden house began as a Mansard-style single-family residence for Sylvester H. Sanborn, a book bindery owner who later served as a city alderman and common councilman. It was one of six mansions erected for prosperous local businessmen when upper Magazine Street was a fashionable district. In 1900 owner Ernst Flentje had it converted into a three-story apartment building, designed by architect William Clark in an elaborate Colonial Revival style. Twin curved, three-tier porches form a heart-shaped plan with swell-front bays. A Cambridge survey director called it the most exaggeratedly elaborate three-decker in Cambridgeport. The conversion reflects shifting social conditions: the first generation of mansion owners was dying off, and electrified street cars after 1895 drew a new middle class to the area. The house illustrates how the three-decker gained acceptance through decorative detail, and it was listed for its association with that trend and for its architecture.","period_of_significance":null,"architect_builder":"William Clark, architect (1900 remodelling); Ernst Flentje, owner who converted it","architectural_style":"Colonial Revival (remodelled 1900 from a Mansard-style house)","criteria":["A","C"],"status_note":"Present use is residential.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:11:58.041642-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/30/7904/63790430/content/electronic-records/rg-079/NPS_MA/83000800.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/83000800/f0d9081331-800.webp","url_1600":"https://nationalhistoricalregister.com/media/83000800/f0d9081331-1600.webp","licence":"Public domain","author":"Daderot","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Ernst_Flentje_House_-_129_Magazine_Street,_Cambridge,_MA_-_IMG_4180.JPG\" rel=\"noopener\">Daderot</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Ernst_Flentje_House_-_129_Magazine_Street,_Cambridge,_MA_-_IMG_4180.JPG"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/63790430","wikipedia":"https://en.wikipedia.org/wiki/Ernst_Flentje_House","wikidata":"https://www.wikidata.org/wiki/Q5394983"},"indexable":true,"url":"https://nationalhistoricalregister.com/massachusetts/middlesex-county/flentje-ernst-house-83000800/"}