[1] The 3-inch M1917 anti-aircraft gun was the first United States Army dedicated anti-aircraft gun, being in service throughout World War I and early World War II.

It was only deployed in limited quantities on fixed mounts.

It was soon supplemented by a newer mobile model, the 3-inch M1918 anti-aircraft gun.

A majority of the completed guns were deployed with the United States Army Coast Artillery Corps (CAC) at seacoast forts during and after World War I.

The gun type had lasted 25+ years and more of military usage, specifically through two World Wars.