{"nrhp_refnum":"82002200","name":"Battery John Barlow and Saxton","other_names":["Battery Barlow Saxton"],"category":"structure","location":{"address":"Fort MacArthur","address_restricted":false,"city":"San Pedro","county":"Los Angeles County","state":"CA","lat":33.716232664000074,"lon":-118.29565316799994,"geom_source":"nps_gis"},"listed_date":"1982-05-04","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Military","Engineering"],"significance_levels":["local"],"summary":{"what_it_is":"A coast artillery (harbor defense) mortar battery on the former Upper Reservation of Fort MacArthur, Palos Verdes Peninsula, San Pedro, California. Construction began in 1915 and finished in 1919, built by the U.S. Army Corps of Engineers.","why_significant":"The nomination presents it as a representative harbor defense emplacement of the 1915-1945 coast defense system built to protect Los Angeles Harbor. It is described as the only surviving example in the continental United States of Taft Board fortifications designed to support seacoast mortars. The reviewer recommended acceptance under criteria A and C.","narrative":"Battery Barlow Saxton is a reinforced concrete mortar battery on the former Upper Reservation of Fort MacArthur in San Pedro. It was built between 1915 and 1919 for $290,300 to hold eight 12-inch long-tube mortars, which were mounted by December 1916. Underground magazines, gallery entrances, a communications tunnel and a serpentine entry passage form the main structure, while two plotting and survey rooms behind the gun positions converted observation data into aiming information. The battery was one of the main coast artillery positions meant to defend Los Angeles Harbor. Its significance lies in its link to the coast defense program shaped by the Endicott and Taft Boards. Because of limited funds, the only Taft Board positions built in the continental United States were at Fort MacArthur, and this is the only surviving one designed for mortars. Its mortars never fired at an enemy vessel. After World War II the guns were scrapped and only minor changes followed, so the position could be restored with ease.","period_of_significance":"1915-1945","architect_builder":"U.S. Army Corps of Engineers","architectural_style":null,"criteria":["A","C"],"status_note":"Used for storage and described as occupied; the guns were scrapped after World War II and classrooms were added in the former shell storage areas. Latrines, lighting and the original electrical panel remain.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:55:31.916405-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_CA/82002200.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/82002200/faa2443f41-800.webp","url_1600":"https://nationalhistoricalregister.com/media/82002200/faa2443f41-1600.webp","licence":"Public domain","author":"Related names: Office of the Quartermaster General, U.S. Army Construction Division, Office of Quartermaster General","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:BLDG._-105;_DOUBLE_N.C.O._QUARTERS;_SOUTH_AND_EAST_FACADES_(4166-21)_-_Fort_MacArthur,_Pacific_Avenue,_San_Pedro,_Los_Angeles_County,_CA_HABS_CAL,19-SANPE,2-29.tif\" rel=\"noopener\">Related names: Office of the Quartermaster General, U.S. Army Construction Division, Office of Quartermaster General</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:BLDG._-105;_DOUBLE_N.C.O._QUARTERS;_SOUTH_AND_EAST_FACADES_(4166-21)_-_Fort_MacArthur,_Pacific_Avenue,_San_Pedro,_Los_Angeles_County,_CA_HABS_CAL,19-SANPE,2-29.tif"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/123858949","wikipedia":null,"wikidata":"https://www.wikidata.org/wiki/Q108874024"},"indexable":true,"url":"https://nationalhistoricalregister.com/california/los-angeles-county/battery-john-barlow-and-saxton-82002200/"}