In 1871, beleaguered Parisians used balloons to carry mail out of their city. A headline in the New York Times on February 4, 1871 referred to the "Latest by Balloon Mail," from the city, "from our special correspondent, and dated January 12, 1871." In the first part of the 20th century, German Zeppelins carried mail across continents and oceans. In the U.S., however, balloon mail never advanced out of the fad phase.
The National Postal Museum has a number of items in its collections that were carried by balloons and airships including the Zeppelins.