The first World War cost the federal government more than $30 billion (the entire federal budget for 1913 was $970 million). To offset this enormous expenditure, the Treasury was authorized to sell bonds, with the first $30,000 of interest tax exempt. Through the Liberty Bond program, the government raised about $17 billion for the war effort. Subscribing to the bonds became a symbol of patriotic duty and introduced the idea of financial securities to many Americans for the first time.