You have overlooked what may have been the largest factor of the Great Depression. Stock market panics and agricultural problems had occurred plenty of times before this. What made the Depression different was a collapse in the American banking system that began around 1930. 30% of the American money supply evaporated as small banks failed throughout the country. This was a deflationary event without parallel, and made the American recession far greater than that of the rest of the developed world.
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