On December 1, 1911, the U.S. Post Office Department issued its first and only Registration stamp. The U.S. first implemented a registered letter system on July 1, 1855. For the next 56 years, mailers could pay the registration fee, which ranged from five to twenty cents over these years, with cash or stamps. Though there wasn’t a Registered Mail stamp issued during this time, there were Post Office Seals, also known as Official Seals. They had no franking power, meaning they didn’t pay for the delivery of mail, but they did serve an important purpose. The first official seals had one specific role: to seal large “registered packages” containing registered letters that were being transported, thereby preventing tampering with this very secure class of mail.