I've written a little about the Bonus Army before, and as it seems relevant for you now, I'll drag that up and expand on it a little bit!
In the US, there wasn't something approaching the benefits of the WWII GI Bill seen after World War I, and initially, there was pretty much nothing at all. Following several years of lobbying, it was eventually decided that service men would receive a bonus, but under the Adjusted Compensation Act of 1924, they would only be issued a Certificate, which didn't actually mature for another 20 years:
The Bonus would be awarded as a deferred interest-bearing certificate payable in 1945 or, at death, to the veteran's beneficiaries. In 1945, veterans would receive compensation of a dollar for every day in service, overseas veterans $1.25 per day, plus the accumulated 4 percent interest. Moreover, as part of the bill, after two years veterans would be allowed to take out a 22.5 percent loan from the Veterans Bureau on their certificates' face value. Including interest, this total value could reach as high as sixteen hundred dollars.
The Veterans of Foreign Wars, which was the group advocating for benefits to the veterans, wasn't pleased with the delay, but if nothing else, everyone agreed it was better than nothing at all, even if many veterans were in less than economic comfort. The disappointment in not getting an immediate pay out at the time was one thing, but it seriously ramped up a few years later when the Great Depression hit. Many veterans had already opted to get loans as provided for in the bill in the years before the Depression, pointing to their precarious economic position, and things certainly didn't improve after. Veterans of WWI were affected just like anyone else could be, and it was no doubt incredibly painful knowing there was all that money with their name on it which they couldn't touch! The VFW had already been advocating since passage for immediate payout, and demands kicked into overdrive, and while Congress did act to help Veterans in small ways, such as the 1930 Veteran Relief Act which assisted some 150,000 disabled veterans receive pensions previously denied to them, action on the Bonus payout was always "next year", despite the fact that the unemployment rate for veterans was 50 percent higher than non-veterans according to the VA at the time.
Advocacy, rallies, marches, petitions... the VFW, American LEgion, and other veterans' orgs continued to stump for the Bonus and got at least some relief with the Adjusted Compensation Act in early 1931, passed over Hoover's veto, which increased the loan amount to 50 percent of the total. It was insufficient though, as millions of veterans, desperate for anything, quickly took the maximum and continued to demand the entire payout.
The next legislation, known as the Patman Bill began to work its way through Congress in the spring of 1932, and in support of it, that May, 300 veterans left Oregon by train for Washington, DC. Well publicized, many more, often with families in tow, joined them along the way culminating in an 'Army', including many of their wives and children with them, marching on Washington in the summer of 1932, numbering in the tens of thousands. They camped themselves across the Anacostia River in DC, peacefully protesting for the government to pay out their bonus early.
The Patman Bill which the marchers had been hoping to see pass, did not. The House voted approvingly on it, but the Senate shot it down in a vote on June 17th (and it would have faced a veto from Hoover in any case), so after two months of their presence, President Hoover wanted them gone. Some of their number, deflated by the loss, did choose to go voluntarily - the government had even offered transportation for them, but many more remained encamped and wouldn't budge. No action was taken immediately, but on July 28th the police attempted to remove them, without success, and resulting in the shooting of two veterans. Following this failure, Army Chief of Staff Douglas MacArthur was detailed to evict them from their camp site. Possibly wires were crossed in the conveying of orders, since while Hoover requested "every kindness and consideration” be shown in removing them, given the presence of so many women and children, MacArthur was told by the Secretary of War to “Proceed immediately to the scene of disorder [and] surround the affected area and clear it without delay.” MacArthur was certainly no friend of the marchers, having only a month prior giving the commencement speech at University of Pittsburgh decrying the "forces of unrest" and writing in an article from the same period equating many of the government critics with Communism (the Communist Party did have a presence at the encampment but was in no way the organizer, or the majority of participants).
Infantry and cavalry, supported by a small detachment of tanks (commanded by Col. Patton), closed on the "Bonus Army", who did not want to go quietly (MacArthur's aide, Major Eisenhower, also was present). Advancing with fixed bayonets, the infantry pushed forward. Realizing that a disaster was at hand, Hoover rescinded his order, relaying a message to MacArthur not to enter the camp, but despite receiving them, he ignored them, the troops entered. The New York Times described the scene thus:
Flames rose high over the desolate Anacostia flats at midnight tonight and a pitiful stream of refugee veterans of the World War walked out of their home of the last two months, going they knew not where.
And the Daily News, a Republican leaning paper, lamented:
The mightiest government in the world chasing unarmed men, women and children with Army tanks. If the Army must be called out to make war on unarmed citizens, this is no longer America.
Fires broke out and tear gas was used, resulting in the death of a young child still in the camp, and numerous marchers were wounded as well. Afterwards, MacArthur described his actions as having prevented a possible revolution that would have threatened the government itself, but few saw it that way, and the image of MacArthur beating on poor, destitute veterans just looking for help earned him some serious critics both in the public, as well as the incoming Roosevelt administration, whose election later that year was certainly helped by the bungled episode. Upon hearing what happened, FDR had flatly stated that MacArthur had just won him the election. Of course it should be noted that when, in 1936, Congress finally relented and gave them their bonus 9 years early, it was over FDR's veto, although in 1933, he had worked to help several hundred enter the CCC despite being over the enlistment age.
As for the other military leaders present, Patton was less sure of what he had done, having discovered in the ranks of the marchers Joe Angelo, his World War I orderly who had saved his life during the war, but nevertheless believed the marchers represented a danger. Eisenhower on the other hand was highly critical of his boss's actions, noting "I told that dumb son-of-a-bitch not to go down there," and further opining that had MacArthur listened to Hoover when told not to enter the camp, the disaster would have been averted.
It should also be noted that this dark episode was a large part of the impetus for the GI Bill of World War II, essentially an effort to correct course and ensure that the same thing wouldn't happen again. After essentially failing the veterans of World War I, Congress wanted to ensure returning veterans would have every possible opportunity to reintegrate into American society and prosper.
Sources:
Stephen R. Ortiz. "Rethinking the Bonus March: Federal Bonus Policy, the Veterans of Foreign Wars, and the Origins of a Protest Movement." Journal of Policy History 18, no. 3 (2006): 275-303
"The Most Dangerous Man in America" by Mark Perry
"Patton" by Alan Axelrod
"FDR" by Jean Edward Smith