The "Bonus Army" refers to:
a) Those Americans who went to Spain to volunteer to fight for the Spanish Republic against the Fascists.
b) The large group of American World War I veterans who went to Washington D.C. at the height of the Great Depression to stage a demonstration because the Federal Government refused to help them.
c) The large numbers of Americans who were forced to pay higher income taxes because the collapse of the economy resulted in lower tax revenues to the U.S. Government.