{"nrhp_refnum":"73000692","name":"Carroll County Courthouse","other_names":[],"category":"building","location":{"address":"Courthouse Sq.","address_restricted":false,"city":"Mount Carroll","county":"Carroll County","state":"IL","lat":42.10057111900005,"lon":-89.97845754899998,"geom_source":"nps_gis"},"listed_date":"1973-11-26","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Architecture"],"significance_levels":["state"],"summary":{"what_it_is":"A three-story masonry county courthouse on a knoll in the center of the town square in Mt. Carroll, Carroll County, Illinois, built in 1858. Plans were drawn by the Chicago firm of Olmsted and Nicholson.","why_significant":"The nomination argues that its Victorian Italianate design, which keeps remnants of Greek Revival such as Doric pilasters and a rectangular sidelit and transomed door, produces a pleasing mixture of the two styles. It describes the design as seemingly unequalled among Illinois courthouses of the same period. The building also sits in harmony with the nineteenth-century structures around the square.","narrative":"Carroll County's courthouse occupies a knoll at the center of the Mt. Carroll town square. Built in 1858 to plans by the Chicago firm of Olmsted and Nicholson, it rises three stories, with a ground floor of rock-faced Galena limestone and upper stories of locally made brick joined by Doric pilasters and tall arched windows. Construction cost $31,500, well above the original estimate of $12,000 to $20,000. It was the first county building to house all county offices and the jail under one roof, and it served briefly as barracks for Carroll County enlisted men in 1861. The building has been used continuously since its completion. Its Italianate design retains Greek Revival details, including the pilasters and the simple sidelit entry door, and the nomination considers it unmatched among Illinois courthouses of its period. Later changes include a replaced entrance staircase, attached additions and modernized interiors.","period_of_significance":"19th Century","architect_builder":"Plans by Olmsted and Nicholson of Chicago; contractor William T. Miller; Jacob P. Emmert, builder; James Watson, stonework; James and B. H. Hallett, brickmasons","architectural_style":"Victorian Italianate with Greek Revival remnants","criteria":[],"status_note":"In continuous use since 1858; condition listed as fair and altered, with modernized offices and additions to the east and north.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:55:35.817867-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/68/8917/28891768/content/electronic-records/rg-079/NPS_IL/73000692.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/73000692/1eab45dfe2-800.webp","url_1600":"https://nationalhistoricalregister.com/media/73000692/1eab45dfe2-1600.webp","licence":"CC BY-SA 3.0","author":"JERRYE &amp; ROY KLOTZ MD","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:CARROLL_COUNTY_COURTHOUSE.jpg\" rel=\"noopener\">JERRYE &amp;amp; ROY KLOTZ MD</a>, <a href=\"https://creativecommons.org/licenses/by-sa/3.0\" rel=\"license noopener\">CC BY-SA 3.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:CARROLL_COUNTY_COURTHOUSE.jpg"},"district":{"nrhp_refnum":"80001340","name":"Mount Carroll Historic District","url":"https://nationalhistoricalregister.com/districts/illinois/mount-carroll-historic-district-80001340/"},"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/28891768","wikipedia":"https://en.wikipedia.org/wiki/Carroll_County_Courthouse_(Illinois)","wikidata":"https://www.wikidata.org/wiki/Q15207686"},"indexable":true,"url":"https://nationalhistoricalregister.com/illinois/carroll-county/carroll-county-courthouse-73000692/"}