{"nrhp_refnum":"66000675","name":"American Philosophical Society Hall","other_names":["See Also:Independence National Historical Park"],"category":"building","location":{"address":"Independence Sq.","address_restricted":false,"city":"Philadelphia","county":"Philadelphia","state":"PA","lat":39.948631854500036,"lon":-75.1494587580508,"geom_source":"nps_gis"},"listed_date":"1966-10-15","is_nhl":true,"nhl_designated_date":"1965-01-12","areas_of_significance":["Science","Religion","Social History","Invention"],"significance_levels":["national"],"summary":{"what_it_is":"The American Philosophical Society Hall is a two-and-a-half story rectangular brick building on South Fifth Street in Independence Square, Philadelphia, Pennsylvania. It was built in the Late Georgian manner and completed in 1789 for the American Philosophical Society.","why_significant":"The nomination argues the building is significant as the home of one of America's oldest learned and scientific societies, whose origins trace to Benjamin Franklin's 1743 call for a society and whose 1768 merger formed the organization that exists today. It also cites the society's early scientific work, including observations of the 1769 transit of Venus and the publication of its Transactions from 1771, and its library and collections.","narrative":"Built in Late Georgian style on a lot awarded by the Pennsylvania Assembly in 1785, this two-and-a-half story brick hall on South Fifth Street in Independence Square was completed in 1789 and held its first meeting that year. Its hip roof had two gabled dormers on the east and west faces, and its central doorways carried a round arch over a basket-weave fanlight. The building housed the American Philosophical Society, founded by Benjamin Franklin's circle and merged with a rival group in 1768. Its significance rests on the society's early scientific work, including observations of the 1769 transit of Venus and the first volume of its Transactions in 1771. The hall also served as a museum and a place where inventions such as John Fitch's steamboat were exhibited. Its library holds the Lewis and Clark Expedition records, the Mason and Dixon records and a large Franklin collection. A third story added in 1890 was removed in 1946 to restore the original appearance.","period_of_significance":"1768-1789","architect_builder":null,"architectural_style":"Late Georgian","criteria":["A","B"],"status_note":"The third story added in 1890 was removed in 1946 to restore the historic appearance; the library is now housed across Fifth Street.","vacant_flag":null,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:28.928438-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/66000675_NHL.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/66000675/fe56af3f2b-800.webp","url_1600":"https://nationalhistoricalregister.com/media/66000675/fe56af3f2b-1600.webp","licence":"CC BY-SA 4.0","author":"Beyond My Ken","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:American_Philosophical_Society_Hall.jpg\" rel=\"noopener\">Beyond My Ken</a>, <a href=\"https://creativecommons.org/licenses/by-sa/4.0\" rel=\"license noopener\">CC BY-SA 4.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:American_Philosophical_Society_Hall.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71994351","wikipedia":"https://en.wikipedia.org/wiki/Philosophical_Hall","wikidata":"https://www.wikidata.org/wiki/Q7186170"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/philadelphia/american-philosophical-society-hall-66000675/"}