American observation balloon service in World War I
United States Army Balloon Squadrons and companies organized under the Aviation Section, U.S. Signal Corps and served overseas with the United States Army Air Service before and during World War I. There were also French, British, and German Balloon Corps. The History of military ballooning includes the American Civil War era Union Army Balloon Corps and the even earlier French Aerostatic Corps. At the start of World War I, the organization of the Air Service of the American Expeditionary Force included observation balloon units organized into companies, squadrons, and wings and each  company was equipped with one balloon. Five companies comprised a squadron, and three squadrons made up a wing. By the end of the war 110 companies had been created. In the field Balloon companies were allotted to the ground units they supported as needed. In 1918 June, with squadron organization discontinued, company designations were numbered and organized into groups. Only 35 companies made it to France with the American Expeditionary Force (AEF). 17 companies served at the front, making 1,642 combat ascensions, while six other groups were en route to the front at the armistice. After the war, the National  Association of American Balloon Corps Veterans was organized and published a history of the service: "Eyes of the Army : a story about the Observation Balloon Service of World War I" by Craig S. Herbert. The group published a quarterly newsletter titled "Haul Down and Ease Off".