The Bonus Army was what they called the 43,000 marchers, comprised of 17,000 World War I veterans, their families, and other groups, who came to Washington, D.C. in the spring and summer of 1932 to demand immediate cash payment of their service certificates.
The march took place at a time when many of the veterans had already been out of work since the beginning of the Great Depression a few years earlier. In essence, they were asking that compensation due to them for wartime service that was not redeemable until 1945 be paid immediately.
Rather than being met by the compassion one might expect for soldiers who had served their country, they were driven out, along with their wives and children, by infantry and cavalry supported by six tanks with none other than Douglas MacArthur in command.
Today the right-wing likes to warn that progressives are encouraging "class warfare" by pointing to the growing gap between rich and poor and the diminishing opportunities for the middle class and the poor to sustain themselves.
I would suggest that progressives are not so much encouraging mass protest as they are amazed that it is taking so long to come together. When growing numbers are having a difficult time taking care of their families through no fault of their own, they are likely to move beyond asking politely for their fair share. It's not a call to class warfare. It's a statement of fact.
(Cross-posted at Lippmann's Ghost.)