The 109th Armor Regiment, part of the Tennessee Army National Guard, has a rich history and a distinctive unit insignia. The regiment's insignia features a shield with alternating bars of color, symbolizing the unit's service in various theaters and conflicts. The crest includes a gold sun and fleur-de-lis, representing service in the Asiatic-Pacific Theater and France during World War II, respectively. The motto "Unleashed Lightning" reflects the regiment's commitment to swift and decisive action in battle. The insignia was originally approved for the 173d Tank Battalion on September 15, 1955, and was redesignated for the 109th Armor Regiment on October 6, 1960. The insignia was amended to change the symbolism on September 30, 1969.