{"nrhp_refnum":"89000343","name":"Marseilles Hydro Plant","other_names":["The Marseilles Development","Marseilles Hydro Development","Mars"],"category":"district","location":{"address":"Commercial St.","address_restricted":false,"city":"Marseilles","county":"LaSalle County","state":"IL","lat":41.326808217000064,"lon":-88.715305117258,"geom_source":"nps_gis"},"listed_date":"1989-05-09","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Historic - Non-Aboriginal","Transportation"],"significance_levels":["state"],"summary":{"what_it_is":"A 7.6-acre hydroelectric power complex on the north bank of the Illinois River at the southwestern edge of Marseilles, La Salle County, Illinois. Its generator building was begun in 1906 and completed in 1911 for the Northern Illinois Light and Traction Company.","why_significant":"The station supplied power to the state's first electric traction railway, the interurban line that linked the Illinois River Valley towns and connected them to wider markets. The nomination argues the interurban helped revitalize towns along the abandoned Illinois and Michigan Canal. The ruined steam plant site is also significant for its potential to yield knowledge of early 20th century power plant operations.","narrative":"Beside the Illinois River at Marseilles stands a hydroelectric complex built to power an early electric railway. Its main generator building, a Classical Revival structure of concrete, brick and steel, was begun in 1906 and finished in 1911 for the Northern Illinois Light and Traction Company. Engineer C. W. Humphrey directed its design and construction. Water diverted by the Marseilles Dam flows through a head race and forebay to turbines that drive the generators, some of them original Westinghouse and General Electric units still working. The 7.6-acre site also holds a storehouse, an oil shed, the ruins of a coal-fired steam plant used in icy winters, and a 1956 substation. Power from the station fed the interurban lines that ran along the old Illinois and Michigan Canal and connected the valley towns. That role in early electric transportation, along with the archeological potential of the steam plant site, is the basis for the property's listing. Exterior and interior remain largely as built.","period_of_significance":"1911 - 1934","architect_builder":"Humphrey, C. W.","architectural_style":"Late 19th and 20th Century Revivals / Classical Revival","criteria":["A","D"],"status_note":"The station is described as a functional power plant. Much of the original generating equipment still works, and the exterior is largely unaltered apart from maintenance and repair. Only foundations of the coal-fired steam plant remain.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:55:35.96544-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/31/8934/28893431/content/electronic-records/rg-079/NPS_IL/89000343.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/89000343/8c5375a73b-800.webp","url_1600":"https://nationalhistoricalregister.com/media/89000343/8c5375a73b-1600.webp","licence":"Public domain","author":"Jet Lowe","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Marseilles_IL_Marseilles_Hydro_Plant_HAER_1986-1.jpg\" rel=\"noopener\">Jet Lowe</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Marseilles_IL_Marseilles_Hydro_Plant_HAER_1986-1.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/28893431","wikipedia":"https://en.wikipedia.org/wiki/Marseilles_Hydro_Plant","wikidata":"https://www.wikidata.org/wiki/Q6773266"},"indexable":true,"url":"https://nationalhistoricalregister.com/illinois/lasalle-county/marseilles-hydro-plant-89000343/"}