When hot-air and hydrogen balloons finally appeared at the end of the 18th century, Walpole feared that the vessels would quickly become “engines of destruction to the human race.” As it turned out, by the end of 1794, hydrogen balloons were being put to use by French army generals to spy over enemy lines and to direct troop maneuvers. Balloons were also employed in the American Civil War as well as the Franco-Prussian conflicts of the 1870’s. And during the two world wars of the last century, balloons were used extensively by American, British, French, and German troops on reconnaissance missions.

The balloon did become an instrument of death in World War II when the Japanese army sent aloft toward the United States 9,000 unmanned balloons armed with bombs. More than 280 of the explosive-laden balloons reached North America.

1. Unmanned bomb-carrying balloon

2. Barrage balloon

[Credit Line]

Library of Congress, Prints & Photographs Division, FSA/​OWI Collection, LC-USE6-D-004722