The 1937 Ohio River Flood Submerged Entire Ohio Cities and Displaced Over a Million People — Almost Nobody Talks About It Ohio River flood 1937, Great Flood 1937 Ohio, Portsmouth Ohio flood history, southern Ohio flood history, Ohio River disaster 1937, Great Ohio Flood history, Ohio River communities history In January 1937 the Ohio River crested at record levels following weeks of continuous rainfall, submerging every community along Ohio's southern border and displacing over a million people