Even before the Depression, U.S. farmers had been in trouble. Low prices and drought contributed to a national crisis. Farmers lost everything, and foreclosures became frighteningly common. In response, groups of militant farmers in the Midwest attended foreclosure auctions with the intention of bullying prospective buyers so that they would not bid on family fortunes. The intimidation could lead to a lynching if the buyers were not easily cowed. Once the prospective buyers had given up, the farmers would repurchase the farm and any equipment for pennies on the dollar, then give them back to the original owners.

The U.S. Communist Party and other labor groups jumped at the opportunity presented in the Midwest. If a revolution could be started anywhere, it would be in one of the most hard-struck areas of the country. Labor organizers helped rally farmers for protests...