Anti-Aircraft Unit Patch Note: This item is currently in storage. This winged ammunition patch is the insignia for U.S. anti-aircraft units during World War I. With anti-aircraft being in its wartime infancy during WWI, U.S. Army anti-aircraft personnel had to learn in the field. These soldiers quickly gained proficiency in how to set up the weapon and measure size, distance and speed of the target, all by hand, as instruments for this purpose had not yet been developed or produced. The favored field gun of the U.S. Army for anti-aircraft purposes during WWI was the French 75mm Field Gun, Model 1897. Donated by Col. (Ret.) Robert F. Schirmer. Click here to return to the Featured World War I Artifacts index.