This issue repeats the design of the 24¢ red lilac Washington which was released January 7, 1862. The 1861-66 series stamp has a darker lilac color and was released a year later. The Series of 1861-66 In 1861, the United States began printing paper notes to finance its Civil War operations. Since the back of the notes were printed in green, they were commonly referred to as “greenbacks.” At first, the notes were redeemable in coins, but as the war raged on, they became merely promises of the U.S. government to pay. Since the notes had no metal money behind them as security, people began to hoard their gold and silver coins. By 1862, greenbacks were being used more frequently, as coins disappeared from circulation. Eventually, small change vanished completely, and greenbacks were the only currency being used. Since much of what people needed cost less than a dollar, they found themselves faced with an unusual dilemma: how to pay for things without using their precious coins. Soon people were buying a dollar’s worth of stamps and using them as change instead.