In the summer of 1932, tens of thousands of American First World War veterans marched on Washington DC to demand the bonus they'd been promised by the government for their part in the war. It was the height of the Great Depression and many were unemployed and hungry. They called themselves the Bonus Army. Louise Hidalgo talks to author Paul Dickson about their story.Photograph: Bonus Army marchers stage a mass vigil on the steps of the Capitol building in Washington while the Senate debates their case (Copyright: Getty Archive)