On May 8, 1911, the US Navy purchased its first airplane. This date is celebrated as the birth of US naval aviation. Militaries have attempted to use aviation in warfare since the early 1800s. During the Napoleonic Wars, Napoleon sent hot air balloons up to observe enemy movements. Other militaries adopted this tactic, including the US during the Civil War. In 1898, Assistant Secretary of the Navy Theodore Roosevelt suggested that they explore the possibility of using aircraft in naval warfare. Though aviation was still in its infancy, the investigators saw the possibilities and the Navy worked with inventors designing planes. After the Wright brothers showcased their successful planes, they provided the Army with its first aircraft.