A Silver color metal and enamel device 1 1/4 inches (3.18 cm) in height consisting of a shield blazoned: Parti per fess Argent and Azure, in chief a sea lion holding in dexter paw a musket with bayonet Gules, in base a mullet within a wreath both of the first; on a canton of the second a rock of the first charged with a shoulder strap of a second lieutenant of Infantry of 1863 Proper. Attached below and to the sides of the shield a Silver scroll inscribed "ANYWHERE-ANYTIME" in Blue letters.
The Regiment was organized in 1917 at Fort Sam Houston by transfer of men from the 19th. The shield is of the Infantry colors with the station of the Regiment indicated by the sea lion of the Philippines holding the musket in the upper portion of the shield and the device of Texas, the star and wreath, in the lower part denoting the place of birth. The parentage of the Regiment is shown in the canton which displays the crest of the 19th United States Infantry. The 19th was a portion of General George H. Thomas' command at Chickamauga in 1863. At the end of the second day (September 20) the entire Federal line had given way excepting Thomas. The 19th held but it had been so roughly used, four officers and 51 men fit for duty, that at sundown the remains of the entire Regiment was in command of a Second Lieutenant. This is shown by the rock and the shoulder strap.
The distinctive unit insignia was approved on 24 March 1924. It was rescinded/cancelled on 4 March 1976.