{"nrhp_refnum":"70000862","name":"Drydock No. 1","other_names":[],"category":"structure","location":{"address":"Norfolk Naval Shipyard","address_restricted":false,"city":"Portsmouth (Independent City)","county":"Portsmouth","state":"VA","lat":36.82062205700004,"lon":-76.29304170899997,"geom_source":"nps_gis"},"listed_date":"1970-02-26","is_nhl":true,"nhl_designated_date":"1971-11-11","areas_of_significance":["Military","Maritime History"],"significance_levels":["national"],"summary":{"what_it_is":"A granite drydock at the Norfolk Naval Shipyard in Portsmouth, Virginia, begun in 1827 and completed in 1834, and owned by the U.S. Department of the Navy.","why_significant":"It was one of the first two drydocks built in the United States, and the Delaware became the first vessel drydocked in the country here in 1833. During the Civil War the Confederate ironclad Virginia was rebuilt in the dock from the Union frigate Merrimac. The shipyard is described as the oldest naval shipyard in the United States.","narrative":"Drydock Number One sits within the Norfolk Naval Shipyard in Portsmouth, Virginia, and is built of large blocks of Massachusetts granite. Its sides rise in stepped tiers, with two flights of stairs at the land end, and it measures 319½ feet long. Work began in 1827 under an act of Congress for the gradual improvement of the Navy, making it one of the first two drydocks built in the United States. Construction cost $974,365.65 and finished in 1834, though the dock opened on 17 June 1833, when the Delaware became the first vessel drydocked in the country. During the Civil War the Confederate government rebuilt the Union steam frigate Merrimac here as the ironclad Virginia, which attacked the Union fleet in 1862 until the Monitor appeared. The structure survives as originally built apart from a replacement caisson and remains in daily use, nearly two centuries after construction began.","period_of_significance":"19th Century","architect_builder":null,"architectural_style":null,"criteria":[],"status_note":"Excellent condition; survives as originally built except for replacement of the original caisson, and is still in daily use.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:51:57.912121-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/16/6826/41682616/content/electronic-records/rg-079/NPS_VA/70000862.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/70000862/5bf24b65ec-800.webp","url_1600":"https://nationalhistoricalregister.com/media/70000862/5bf24b65ec-1600.webp","licence":"Public domain","author":"National Park Service","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:DrydockNumber1.jpg\" rel=\"noopener\">National Park Service</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:DrydockNumber1.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/41682616","wikipedia":"https://en.wikipedia.org/wiki/Drydock_Number_One,_Norfolk_Naval_Shipyard","wikidata":"https://www.wikidata.org/wiki/Q5309682"},"indexable":true,"url":"https://nationalhistoricalregister.com/virginia/portsmouth/drydock-no-1-70000862/"}