The Bonus Army was a gathering of World War I veterans who decided to embark on a protest to Washington DC. They demanded the advancement of bonus payment for wartime service. A series of compensations and benefits were already passed by Congress but were not going to be paid in full until the next decade.
In an effort to suppress the riots that were occurring, the government sent the army to disperse the group. This decision resulted in violent confrontations that included the use of tear gas and tanks by the army. Many veterans were wounded during these events.