Ohio River flood of 1937

===Illinois===
[[Harrisburg, Illinois|Harrisburg]] suffered flooding from the Ohio River in 1883–1884 and again in 1913. Much of the city, except "Crusoes' Island", a downtown orbit that encircled the town square, was underwater. High water had reached {{convert|30|mi|km}} from the river, and the city was flooded in its position among tributary lowlands of the [[Saline River (Illinois)|Saline River]].<ref name=FLOOD>{{cite book|title=The Ohio-Mississippi valley flood disaster of 1937: Report of relief operations of the American Red cross|first=Norman|last=Davis|publisher=American Red Cross|page=79|year=1938}}</ref> Floodwaters reached nearly {{convert|30|mi|km|-1}} inland and Harrisburg was nearly destroyed. 4,000 within Harrisburg were left homeless and 80% of the city was inundated.<ref name="The Pittsburgh Press page 50">''The Pittsburgh Press'', page 50. United Press, 29 January 1937.</ref> Many flooded mines were deemed condemned which left the local economy crippled.  In 1938, the state of Illinois had completed one of the largest operations of its kind ever attempted in the United States, the removal of more than two and a half billion gallons of flood water from Sahara mine No. 3 near downtown Harrisburg.<ref>''Chicago Daily Tribune'', page 4. United Press, 9 May 1938.</ref> By the time the flood waters had receded, 4000 were left [[homeless]].<ref name="The Pittsburgh Press page 50"/>  Between [[Gallatin County, Illinois|Gallatin County]] and Harrisburg, about {{convert|25|mi|km}} of [[Illinois Route 13]] was covered by {{convert|8.0|to|14.0|ft|m}} of water; motorboats navigated the entire distance to rescue marooned families.<ref name=descriptive>{{cite book|title=Illinois, a Descriptive and Historical Guide|first=Harold|last=Hitchens|publisher=US History Publishers|page=436|year=1947}}</ref> National guard boats were the means of transportation in the city, and several thousand people were transported daily from temporary island to island.<ref>{{cite book|title=An Illinois reader|first=Clyde|last=Walton|publisher=Northern Illinois University Press|page=431|year=1970}}</ref> According to the [[Sanborn Map Company]], Harrisburg in October 1925 had a population of 15,000, and in a revised version by January 1937 the population had fallen to 13,000. Afterwards, the [[United States Army Corps of Engineers|Army Corps of Engineers]] erected a levee north and east of the city to protect it from future floods. The levee has become the official northern and eastern border of the town.

Rural [[Pulaski County, Illinois|Pulaski County]] was functionally left an island by the rising portions of the [[Cache River (Illinois)|Cache River]], which near its mouth flowed in reverse as the Ohio floodwaters forced their way along the Cache to the Mississippi River above [[Cairo, Illinois|Cairo]].<ref name=wall>Wall, J.L.  ''[https://archive.org/stream/moyersbriefhisto00moye Moyers' Brief History of Pulaski County]''. [[Mound City, Illinois|Mound City]]: ''Pulaski Enterprise'', 1944.</ref>{{rp|46}}  The majority of county residents were driven from their homes,<ref name=wall />{{rp|48}} while the riverside county seat, [[Mound City, Illinois|Mound City]], was entirely flooded, with the shallowest locations still lying under {{convert|12|ft}} of water.  Cairo itself was saved only by low water levels on the Mississippi River, which rose only to the highest spots on the levees without surmounting them.<ref name=wall />{{rp|47}}  The historic city of [[Old Shawneetown, Illinois|Shawneetown]] was completely inundated and the residents were forced to move to a tent city on the outskirts. Property damages in the southern Illinois region amounted to more than $75 million ($1.2 billion in 2015). Over three hundred bridges were smashed, six schools were ruined, and twelve hundred submerged homes. Flood waters were recorded at {{convert|65.4|ft}}. Damage in Shawneetown was so cataclysmic the town [[Shawneetown, Illinois|relocated three miles inland]] to higher ground.