A Silver color metal and enamel device 1 1/8 inches (2.86 cm) in height overall consisting of a shield blazoned: Argent, in front of a castle wall embattled and with two sentry towers Azure masoned of the first a palmetto tree issuant from an oak tree eradicated, with branches lopped off, barwise, both Proper. Attached below the shield a Silver scroll inscribed "WHEREVER MY COUNTRY CALLS" in Blue letters.
White and blue are the old and the present Infantry colors. The castle wall symbolizes the walls of Mexico where the Palmetto Regiment saw active service during the Mexican War. The palmetto tree alludes to the regiment of that name and the fort at Sullivan's Island, the station of the regiment. The palmetto and dead oak tree are also prominently featured in the State seal.
The distinctive unit insignia was approved on 4 March 1938. It was amended to add a motto on 15 January 1969.