From The Writer's Almanac:
It was on this day in 1932 that World War I veterans began arriving in Washington, D.C., demanding their military bonuses about 15 years early. Congress had approved the bonuses as a retirement plan back in 1924, and those bonuses weren't supposed to be paid until 1945, when the soldiers had reached the age of retirement. But it was the Great Depression, and most of those veterans were out of work and living in poverty, and they were desperate for early bonuses to help them survive.
The Bonus March was the idea of an unemployed former Army sergeant named Walter Waters, who stood up at a veterans' meeting in Portland, Oregon, on March 15, 1932, and said that every man at the meeting should hop a train to Washington, D.C., and demand the money that was rightfully his.
Walter Waters and his men arrived in Washington, D.C., on this day in 1932. Over the next few months, about 25,000 others joined them. They had been congregating in D.C. for almost a month when the bonus bill finally came to the floor. It was passed by the House of Representatives, but it was defeated in the Senate two days later. Many of the Bonus Marchers went home, disappointed, but the original group of men stayed behind, vowing to remain until they received justice.
President Herbert Hoover ordered the Army to drive them out of town. Several Army battalions of cavalry and tanks advanced on the veterans, tossing tear-gas grenades and setting the shantytown on fire. Over the next week, newspapers and newsreels showed images of veterans fleeing the burning shantytown with their families, through clouds of tear gas and smoke, followed by tanks and mounted troops waving swords. It was a public relations disaster. When presidential candidate Franklin D. Roosevelt read a newspaper article about the eviction, he said, "This will elect me," and he was right.