The Bonus Army was a group of 43,000 demonstrators – 17,000 veterans of U.S. involvement in World War I, their families, and affiliated groups – who gathered in Washington, D.C., in mid-1932 to demand early cash redemption of their service bonus certificates. Organizers called the demonstrators the Bonus Expeditionary Force (B.E.F.), to echo the name of World War I's American Expeditionary Forces, while the media referred to them as the "Bonus Army" or "Bonus Marchers". The demonstrators were led by Walter W. Waters, a former sergeant.

The American Expeditionary Forces (AEF) was a formation of the United States Armed Forces on the Western Front during World War I, comprised mostly of units from the U.S. Army. The AEF was established on July 5, 1917, in France under the command of then-Major General John J. Pershing. It fought alongside French Army, British Army, Canadian Army, British Indian Army, New Zealand Army and Australian Army units against the Imperial German Army. A small number of AEF troops also fought alongside Italian Army units in 1918 against the Austro-Hungarian Army. The AEF helped the French Army on the Western Front during the Aisne Offensive in the summer of 1918, and fought its major actions in the Battle of Saint-Mihiel and the Meuse-Argonne Offensive in the latter part of 1918.