When the United States was ready to release its first stamps in 1847, the Post Office returned to the issues that had first been raised in a debate about coins. It was agreed that only dead or allegorical persons—for example, the Goddess of Liberty—can be depicted on U.S. currencies. The postal service adopted similarly democratic ideals. Had living persons been allowed to appear on U.S. coins, stamps, and banknotes, it would have been possible to depict U.S. citizens who would go on to become traitors to the nation. That tradition continued for both currency and stamps until 1866 when it became codified into law. The country’s first stamp designs featured Benjamin Franklin and George Washington, who had died in the previous century.

Source: Fast Company