In 1917 and 1918 the US Government raised money to help finance the war by selling Liberty Bonds, so named to appeal to the patriotism of Americans. Liberty Bonds were conceived by the Secretary of the Treasury, William Gibbs McAdoo. By buying the Liberty Bonds, Americans were loaning the government money. The US government agreed to repay the money plus interest in a specified number of years. I think this should be the answer.. Hope this will help you a lot. ☺☺