Interesting facts:
• Pocahontas appeared on the back of the $20 bill in 1875.
• You'd need to fold a bill of any denomination about 8,000 times (first forward and then backwards) before it will tear.
• Martha Washington is the only woman whose portrait has appeared on a U.S. currency note. It appeared on the face of the $1 Silver Certificate of 1886 and 1891, along with the back of the $1 Silver Certificate issued in 1896.
• In 1865, the Department of the Treasury issued Gold Certificates, which were backed by gold and bullion deposits. These certificates stayed in circulation until 1933.
• 97% of all paper money contains traces of cocaine.