The idea of aerial military surveillance dates back to the Civil War, when both the Union and the Confederacy used hot-air balloons to spy on the other side, tracking troop movements and helping to direct artillery fire.— Michael Hastings
The idea of aerial military surveillance dates back to the Civil War, when both the Union and the Confederacy used hot-air balloons to spy on the other side, tracking troop movements and helping to direct artillery fire.
