U.S. Postage and U.S. Fractional were the smallest sized paper money issued by the United States government. Because of a shortage of coins, due to hoarding, this money began in 1862 during the Civil War. Fractional currency was issued in six different denominations: 3¢, 5¢, 10¢, 15¢, 25¢ and 50¢. There were five different issues and countless varieties that exist for collectors. For additional study and reading, I can recommend the “Comprehensive Catalog of U.S. Paper Money” by Gene Hessler, BNR Press.