During World War II, all the paper money in circulation in the state was stamped in big outline letters across the back that said “Hawaii.” The fronts had smaller renditions of “Hawaii” stamped on them. And instead of green, the seal was brown. Why did the government do that?

The U.S. Treasury worried that if Japan invaded it would seize hundreds of millions of U.S. currency and could use it to fight the war against the United States.

The Treasury had an idea. If they marked all the bills in circulation, they could be “demonetized” in case they were seized by the Japanese. They would be as valuable as Monopoly money.

All the bills were 1935 silver certificates. Rather than risking sending the $200 million in regular currency back to the mainland, the unmarked bills were taken to the crematory at Oahu Cemetery and the furnace at the Aiea Sugar Mill to be burned.

The only currency available in the state during the war were the bills marked HAWAII. It was illegal to hold the old currency.

The bills remained in circulation until 1946, when the government began replacing them with regular currency. If you held onto some of the bills, they are worth quite a bit today. They range between $20 and $100 from coin stores and on eBay, depending on condition.