{"nrhp_refnum":"68000024","name":"Morrow Plots, University of Illinois","other_names":[],"category":"site","location":{"address":"Gregory Dr. at Matthews Ave.","address_restricted":false,"city":"Urbana","county":"Champaign County","state":"IL","lat":40.10448127900003,"lon":-88.22586680099994,"geom_source":"nps_gis"},"listed_date":"1968-05-23","is_nhl":true,"nhl_designated_date":"1968-05-23","areas_of_significance":["Agriculture"],"significance_levels":["national"],"summary":{"what_it_is":"A fenced agricultural experiment site of about 1.3 acres on the University of Illinois campus in Urbana, Illinois, at the northwest corner of Gregory Drive and Mathews Avenue. The plots were first laid out in 1876 by Prof. Manly Miles.","why_significant":"The plots were the first field experiment plots established by a college in the United States. They helped prove that continuous corn cropping depletes prairie soil and that crop rotation prevents soil exhaustion. They still supply data on rotation and on organic and chemical soil treatments.","narrative":"Set in the middle of the University of Illinois campus in Urbana, the Morrow Plots are a small fenced field where crops have been grown under test since 1876. Prof. Manly Miles laid out the first three half-acre plots, named for George E. Morrow, a strong supporter of the work. Seven more plots were added in 1879, and in 1903 and 1904 the field was cut back to six plots of one-tenth acre each to make room for campus expansion. Three cropping systems are compared: continuous corn, a corn-oats rotation, and a corn-oats-red clover rotation. Since 1904 half of each pair has received manure, limestone and phosphorus. The experiments showed that repeated planting of the same crop lowers the productivity of prairie soil, that rotation guards against exhaustion, and that worn soil can be restored with treatment. Agronomy textbooks have long cited the results, and the plots continue to yield data today.","period_of_significance":"1900- (specific date 1876)","architect_builder":null,"architectural_style":null,"criteria":[],"status_note":"Still in cultivation as six 1/10-acre plots inside a fenced area; the form lists the property as occupied and in agricultural use.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:55:35.474129-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/98/8914/28891498/content/electronic-records/rg-079/NPS_IL/68000024_NHL.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/68000024/9db2c3d675-800.webp","url_1600":"https://nationalhistoricalregister.com/media/68000024/9db2c3d675-1600.webp","licence":"Public domain","author":"Ariescwliang","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:UIUC_morrow_plot.JPG\" rel=\"noopener\">Ariescwliang</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:UIUC_morrow_plot.JPG"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/28891498","wikipedia":"https://en.wikipedia.org/wiki/Morrow_Plots","wikidata":"https://www.wikidata.org/wiki/Q3324432"},"indexable":true,"url":"https://nationalhistoricalregister.com/illinois/champaign-county/morrow-plots-university-of-illinois-68000024/"}