{"nrhp_refnum":"82001959","name":"Mason, Josiah, Jr., House","other_names":[],"category":"building","location":{"address":"11 Market St.","address_restricted":false,"city":"Cambridge","county":"Middlesex County","state":"MA","lat":42.36713442900003,"lon":-71.09400235999993,"geom_source":"nps_gis"},"listed_date":"1982-04-13","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Architecture"],"significance_levels":["state"],"summary":{"what_it_is":"A brick residence at 11 Market Street in Cambridge, Massachusetts, built in 1831 for Josiah Mason, Jr. The architect is unknown, and the house has not been altered or moved.","why_significant":"The nomination argues the house is significant architecturally and historically. It is a rare example of a Federal period side-hall single house, with a Federal brick cornice and a Greek Revival pilaster entrance that marks the emergence of the new style. Its first resident, Josiah Mason, Jr., was a merchant, selectman and state representative.","narrative":"Built in 1831 at 11 Market Street in Cambridge, this brick house was home to Josiah Mason, Jr., a merchant. It is a rare surviving example of a Federal period side-hall single house. The brick cornice is a typical Federal detail, while the pilaster frame around the entrance points to the arrival of the Greek Revival style, so the house captures a moment of stylistic transition. The architect is unknown, and the building has been neither altered nor moved. It still serves as a residence, its original use. Mason also played a part in local affairs. He was among the men who formed the Cambridgeport Meetinghouse Corporation under an act passed in 1805. He served as a selectman from 1828 to 1831 and as a representative in the General Court in 1832. The house was listed for both its architectural character and its link to a figure in Cambridgeport civic life.","period_of_significance":null,"architect_builder":null,"architectural_style":"Late Federal, with Greek Revival pilaster enframement of the entrance","criteria":["A","C"],"status_note":"Present use is residential; the form states the building is unaltered and has not been moved.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:11:54.340002-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/68/7904/63790468/content/electronic-records/rg-079/NPS_MA/82001959.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/82001959/75505343d8-800.webp","url_1600":"https://nationalhistoricalregister.com/media/82001959/75505343d8-1600.webp","licence":"CC BY-SA 3.0","author":"Tim Pierce","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Josiah_Mason_Jr_House.jpg\" rel=\"noopener\">Tim Pierce</a>, <a href=\"https://creativecommons.org/licenses/by-sa/3.0\" rel=\"license noopener\">CC BY-SA 3.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Josiah_Mason_Jr_House.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/63790468","wikipedia":"https://en.wikipedia.org/wiki/Josiah_Mason_Jr._House","wikidata":"https://www.wikidata.org/wiki/Q6290567"},"indexable":true,"url":"https://nationalhistoricalregister.com/massachusetts/middlesex-county/mason-josiah-jr-house-82001959/"}