Postage Stamp Currency
Over the decades, the US has had many types of currency. Some of them were rather strange. Take for example this Fractional Currency, often referred to as postage stamp currency, authorized in July 1862.
Issued in denominations of 5, 10, 25, and 50 cents, these notes were an effect of the US Civil War. When the war started in 1861, fractional silver coinage was hoarded and disappeared from circulation. As a response, people started using postage stamps as money to make change. The problem with this was that postage stamps then started to become scarce, impeding the mail.
The answer that Congress came up with was the printing of Fractional Currency with values under $1. The fastest way to do this was to have the postage stamp printers rework their stamp dies to print banknotes. In effect, the printers just started printing postage stamps on notes. So, for the 50 cent stamp shown, National Bank Note Company just printed 5, 10 cent stamps next to each other. Problem solved!
These notes were produced for about a year until a new series of properly designed Fractional Currency notes was printed and issued.
We need to remember that the current state of the US only having one kind of currency, the Federal Reserve Note, is a recent development and an aberration.