After victory in World War I, the US government promised in 1924 that servicemen would receive a bonus for their service, in 1945. The bonus was also known as the "Tombstone Bonus." Then, the Great Depression hit, beginning with the stock market collapse of 1929. By 1932, the Depression was still dragging on, with no end in sight. Out of sheer desperation, some of the veterans decided to march on Washington to ask for the bonus right away.

If the movement had an official beginning, it would have been in Portland, Oregon. 400 veterans had gathered there by May 17, 1932, under the leadership of a fellow veteran, Walter M. Waters. They began a long trek to Washington aboard a freight train, loaned to them for free by the rail authorities. After exiting the train in Iowa on May 18 they hitched rides and walked the rest of the way to Washington. Smaller splinter groups reached the capital on their own. By June 1, some 1,500 men, some with their families, were in Washington.

They camped out in homemade shanty towns. The major sites included 12th Street and B Street, NW (the latter is now Constitution Avenue), 3rd Street and Pennsylvania Avenue, NW, and the largest, 30 acre site on the Anacostia Flats.