Antique U.S. Military Uniform Button

This item is an antique U.S. military uniform button. From the World War I era (predominantly active from the late 1900s through the early 1920s).   Size: approximately one half inch. Much age patina. Please review pictures.  Design: The back reads CITY BUTTON WORKS NEW YORK stamped around the metal attachment loop (shank).  Front Design: The front of these particular buttons features the United States Great Seal Eagle, which became standard for Army service uniforms starting in 1902. The added metal split-ring running through the shank was a common historical method used to secure buttons onto heavy canvas or wool uniform coats without needing to stitch them directly into the fabric. This allowed the buttons to be easily swapped or removed when cleaning.  Sold as is. From a cat friendly smoker’s home.