When most people think of the "Great Depression", they picture the panic on Wall Street in October 1929. You'll discover how the worst financial collapse in American history began in South Dakota nearly a full decade before the rest of the nation. Get our free mobile appBetween 1920 and 1929, years before the banking panic of the 1930s, over 400 banks in South Dakota failed. South Dakota farmers were suddenly stuck with gigantic mortgages on land and machinery they could no longer afford. Story Sources: A New Deal For South Dakota: Drought, Depression, and Relief, 1920-1941 (R. Alton Lee), Great Plains Quarterly/Center For Great Plains Studies (The Long Depression: Agricultural Crisis of the 1920s), History.SD.GOV