MUD FLOODS: CHICAGO, SEATTLE AND THE RAISED STREET Some photographs really do show windows below the present street level. Some doors really do open below current grade. Some streets really did change elevation. Some buildings really were lifted, moved, remodeled or surrounded by new fill. The photograph can be genuine while the caption is wrong. CHICAGO Chicago is an unusually good case because the city documented its drainage problem and its response. The early city occupied low, wet ground. Sewers needed enough slope to work. Beginning in the 1850s, Chicago undertook a long program of raising street grades. Buildings were lifted with jackscrews so new foundations and street levels could be built beneath them. This is not a theory inferred from one basement window. The Encyclopedia of Chicago describes the decades-long street-raising project, and the Library of Congress Historic American Buildings Survey records the 1869 Water Tower and the changing shoreline and land fill around it. The engineering history of Ellis Chesbrough explains why the city had to alter its grade as part of its sewer and water program. INTERNET: "Why is the original first floor underground?" CHICAGO, 1860: "We raised the goddamn street." That is a Nitetime summary, not a complete engineering report. The report is the important part. SEATTLE Seattle supplies a different but related example. The Denny Regrade leveled part of Denny Hill in stages beginning in the late 1890s and continuing into the early 20th century. The Seattle Municipal Archives describes regrading, filling tidal flats and building infrastructure to make a steep, water- bounded city more usable for commerce and transport. Its finding aid points to photograph albums showing the work, including water cannons sluicing the hill away. OTHER POSSIBILITIES A below-grade opening can also result from road resurfacing, sidewalk reconstruction, retaining walls, landfill, flood control, local excavation, subsidence, an original basement design, a changed entrance or a later addition. One explanation does not fit every photograph. THE METHOD Identify the building. Identify the street. Identify the date. Find the original grade. Search city engineering records, newspapers, maps, permits and photographs. Ask whether the building was raised or the street was raised. A window below today's grade tells us about the relationship between a building and today's grade. By itself it does not tell us when or why that relationship changed. SOURCE: Encyclopedia of Chicago, Street Raising on Lake Street https://www.encyclopedia.chicagohistory.org/pages/3292.html SOURCE: Encyclopedia of Chicago, Multicentered Chicago https://www.encyclopedia.chicagohistory.org/pages/854.html SOURCE: Ellis Sylvester Chesbrough, ASCE historical profile https://www.asce.org/about-civil-engineering/history-and-heritage/notable-civil-engineers/ellis-sylvester-chesbrough/ SOURCE: Seattle Municipal Archives, A City at Work https://www.seattle.gov/city-archives/exhibits-and-education/online-exhibits/a-city-at-work SOURCE: Denny Hill Regrade Photograph Albums https://archives.seattle.gov/finding-aids/repositories/2/resources/451