
The US Army WWI veterans and their families camping on the lawn of the US Capitol in Summer 1932.
The US Bonus Army was a reference used by the media of the WWI American Expeditionary Forces. The Bonus Army Conflict was an incident between the US WWI veterans, their families (together 42 000 demonstrators) and the US Army (500 of infantrymen - 500 of horsemen - 800 policemen - 6 M17 light tanks). Simultaneously with the Bonus Army Conflict also the Great Depression and the Dust Bowl draggled and plagued the US economy and the industry. Many of the US WWI veterans were unemployed and their money was scarce.
In 1924 the US Congress enacted the World War Adjusted Compensation Act, promising to pay subsidies for the 3.6 million US WWI veterans - the value of the total supposed payment in 2018 money is equivalent to $54 billion. Based on the days-in-duty during the war every veteran received a bonus certification, but they could not redeem the certificates until 1948. However, in 1932 many of the war veterans had been hit hardly during the early days of the Great Depression and asked the Congress to redeem their bonus certificates early. President Herbert Hoover and the Republican congressmen refused such a action as any potential economy recovery would be slowed in case of early redeems.

In order to suppress the US Bonus Army demonstrators the US Army used M17 tanks for instance. Probably the only time the US has used tanks against its own people.
It was not only the demonstrators, but also many ordinary Americans were outraged - how could the Congress treat the WWI veterans with a such a disrespect, 20% of the demonstrators were disabled. Later and after the conflict Hoover was heavily criticized using excessive actions against the US Bonus Army veterans.
Most of the Bonus Army camped in "Hooverville" (a shanty town built by the homeless during the Great Depression). Remonstrating, they organized parades, marching against the Congress and Hoover demanding the early redeeming of the certificates. The US Senate voted about the Bonus Bill on June 17th and the Bonus Army massed at the US Capitol. The Bonus Bill was defeated by Senate voting. On July 28th Hoover ordered the US Army to disperse the protesters. Infantry, cavalry, machine gunners and tanks pushed the protesters out of Washington injuring more than 1 000 marchers during the Bonus Army Conflict. Later on, back in the "Hooverville" the police shot two veterans whom died afterwards.
Overall, the US Army and the police intervention in order to suppress the protest was violent with cavalry charging and infantry using fixed bayonets and tear-gas. After hitting the "Hooverville", tearing down and burning the "Bonusers" campsite Hoover ordered to stop the assault, however General Douglas MacArthur ignored the President's command, claiming that the Bonus March was an attempt to overthrow the US Government MacArthur ordered a new attack chasing down the routed protesters - the veterans, their wives and children were driven out, all their shelters and belongings burned.
The Bonus Army Conflict was disastrous for Hoover and while also unable to resolve the miseries by the Great Depression this event is considered as a contributor factor Hoover losing the 1932 elections. After the second Bonus March in 1933, the US Congress decided to pay the subsidies in 1936.