{"nrhp_refnum":"66000217","name":"U.S. Customhouse","other_names":["Old Customhouse"],"category":"building","location":{"address":"Calle Principal at Decatur St.","address_restricted":false,"city":"Monterey","county":"Monterey County","state":"CA","lat":36.60321710600007,"lon":-121.89342575944656,"geom_source":"nps_gis"},"listed_date":"1966-10-15","is_nhl":true,"nhl_designated_date":"1960-12-19","areas_of_significance":["Architecture"],"significance_levels":["national"],"summary":{"what_it_is":"The Old Custom House at 115 Alvarado Street in Monterey, California, is a long adobe and rock building with two-story wings. Its oldest part dates to 1827, and it was enlarged by Thomas O. Larkin in 1841-46. It is owned by the State of California and open as a museum.","why_significant":"The nomination calls it an excellent example of the Monterey Colonial style applied to a public building, and the oldest public building still standing on the West Coast. It was the only custom house in Mexican California until 1845, and Commodore John D. Sloat raised the American flag here on July 7, 1846.","narrative":"Built in 1827 by the Mexican Government as a small two-room adobe, the Old Custom House in Monterey grew into a long, one-story, tile-roofed building of adobe and rock with two-story hip-roofed wings at each end. Thomas O. Larkin, an American merchant and master-builder, added the second story of the north wing, the central section and the south wing between 1841 and 1846. Verandas were added on the ocean side. The building measures 135 by 34 feet. It served as the only custom house north of Mexico until 1845, collecting duties on the California hide and tallow trade that largely funded Mexican government operations. On July 7, 1846, Commodore John D. Sloat raised the American flag here and proclaimed California part of the United States. After use as a U.S. custom house, a residence and a lodge hall, it was restored and became a state museum in 1930. It is an example of Monterey Colonial public architecture.","period_of_significance":"1827, 1841-42 (specific dates)","architect_builder":"Thomas O. Larkin (1841-46 enlargement, under contract with the Mexican Government); original 1827 section erected by the Mexican Government","architectural_style":"Monterey Colonial","criteria":[],"status_note":"Restored, maintained in excellent condition, and open to visitors as a museum and State Historical Monument.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:55:31.906795-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_CA/66000217_NHL.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/66000217/bc69862478-800.webp","url_1600":"https://nationalhistoricalregister.com/media/66000217/bc69862478-1600.webp","licence":"CC BY-SA 3.0","author":"Jsweida","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Custom_House_Monterey,_CA.jpg\" rel=\"noopener\">Jsweida</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:Custom_House_Monterey,_CA.jpg"},"district":{"nrhp_refnum":"70000137","name":"Monterey Old Town Historic District","url":"https://nationalhistoricalregister.com/districts/california/monterey-old-town-historic-district-70000137/"},"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/123857978","wikipedia":"https://en.wikipedia.org/wiki/Old_Custom_House_(Monterey,_California)","wikidata":"https://www.wikidata.org/wiki/Q7083808"},"indexable":true,"url":"https://nationalhistoricalregister.com/california/monterey-county/u-s-customhouse-66000217/"}