From the ArcaMax Publishing, Trivia Newsletter:
http://www.arcamax.com/news/trivia/s-388475-488152
As early as 1822, the postmaster in Washington, D.C. was worried by the amount of extra mail at Christmas time. His preferred solution to the problem was to limit by law the number of cards a person could send. Even though commercial cards were not available at that time, people were already sending so many home-made cards that sixteen extra postmen had to be hired in the city.
This news arrived on: 08/04/2008