"From 1863 to 1935, National Bank Notes were issued by banks throughout the country and in U.S. territories. Banks with a federal charter would deposit bonds in the U.S. Treasury and then would be able to issue National Bank Notes. The federal government would back the value of the National Bank Notes. National Bank Notes were retired as a currency in the 1930s during the great depression and was consolidated into Federal Reserve Notes, United States Notes, and Silver Certificates."
(from www.treasuredstocks.com)