{"nrhp_refnum":"66000314","name":"First Self-Sustaining Nuclear Reaction, Site of","other_names":["The Enrico Fermi Memorial"],"category":"site","location":{"address":"S. Ellis Ave. between E. 56th and 57th Sts.","address_restricted":false,"city":"Chicago","county":"Cook County","state":"IL","lat":41.792448429000046,"lon":-87.60109350199997,"geom_source":"nps_gis"},"listed_date":"1966-10-15","is_nhl":true,"nhl_designated_date":"1965-02-18","areas_of_significance":["Science"],"significance_levels":["national"],"summary":{"what_it_is":"A site on the University of Chicago campus, on the east side of South Ellis Avenue, where a squash-rackets court under the West Stands of Stagg Field housed the first self-sustaining nuclear reactor. The stands were demolished in 1958, and the Enrico Fermi Memorial with Henry Moore's sculpture 'Nuclear Energy' now marks the spot.","why_significant":"On December 2, 1942, scientists led by Enrico Fermi achieved the first controlled, self-sustaining nuclear chain reaction in the 'Chicago Pile' here. The experiment gave humanity a means of releasing nuclear energy and was central to the wartime effort to develop an atomic bomb. The site is marked by a memorial sculpture installed in 1967.","narrative":"A grassy plot on the University of Chicago campus marks the place where the nuclear age began. Beneath the West Stands of Stagg Field, a converted squash-rackets court measuring 30 by 60 feet held the 'Chicago Pile,' a stack of graphite bricks and uranium oxide built under Enrico Fermi's direction. On December 2, 1942, after a day of stops and restarts, Fermi and his colleagues watched the pile become self-sustaining and run for twenty-eight minutes. The work was part of the American effort to produce an atomic bomb. The vine-covered West Stands were demolished in 1958 because of radiation and unsound condition, and a library now occupies much of the old field. In 1967 a twelve-foot bronze sculpture by Henry Moore, titled 'Nuclear Energy,' was dedicated on the spot. Plaques beside it identify the site as a national historic landmark. The nominated area is under one acre.","period_of_significance":"1942","architect_builder":"Sculptor Henry Moore (memorial sculpture)","architectural_style":null,"criteria":[],"status_note":"The West Stands were torn down in 1958; the site is now a memorial plot with the Henry Moore sculpture, listed in excellent condition and publicly owned.","vacant_flag":null,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:55:35.114244-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/82/8915/28891582/content/electronic-records/rg-079/NPS_IL/66000314_NHL.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/66000314/d27a78a640-800.webp","url_1600":"https://nationalhistoricalregister.com/media/66000314/d27a78a640-1600.webp","licence":"Public domain","author":"Melvin A. Miller of the Argonne National Laboratory","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Stagg_Field_reactor.jpg\" rel=\"noopener\">Melvin A. Miller of the Argonne National Laboratory</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Stagg_Field_reactor.jpg"},"district":{"nrhp_refnum":"12000040","name":"Chicago Park Boulevard System Historic District","url":"https://nationalhistoricalregister.com/districts/illinois/chicago-park-boulevard-system-historic-district-12000040/"},"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/28891582","wikipedia":"https://en.wikipedia.org/wiki/Chicago_Pile-1","wikidata":"https://www.wikidata.org/wiki/Q284681"},"indexable":true,"url":"https://nationalhistoricalregister.com/illinois/cook-county/first-self-sustaining-nuclear-reaction-site-of-66000314/"}