APMEX offers a superb selection of Hawaii Currency issued during World War II. Following the attack on Pearl Harbor, military officials were worried that, in the event of a full-on Japanese invasion, Japanese forces would have access to large amounts of U.S. currency. On January 10, 1942, Military Governor Emmons ordered all U.S. paper money be recalled, except $200 for individuals and $500 for businesses. In June 1942, new currency notes were printed with the word "Hawaii" overprinted on both sides of the bill. The idea behind this was, should there be an invasion, the U.S. government could declare any Hawaii-stamped notes worthless.