The "Bonus Army"

'On July 28, 1932, protesters known as the "Bonus Army," or "Bonus Expeditionary Forces (B.E.F.)," who had gathered in the nation's capital to demand an immediate lump-sum payment of pension funds (benefits) for their military service during World War I, were confronted by Federal troops (cavalry, machine-gunners, and infantry) following President Herbert Hoover's orders to evacuate. (While Congress had approved the payment in 1924, the bonus was not payable until 1945.)
The presence of the Bonus Army was a continuing embarrassment and source of difficulty for Hoover. He sent in troops under the command of Brigadier Perry L. Miles and General Douglas MacArthur. The veterans faced tear-gas bombs, bayonets, and tanks.' - Library of Congress