An unidentified balloon in flight.
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.
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.