A Gold color metal and enamel device 1 1/4 inches (3.18 cm) in height overall consisting of a shield blazoned: Argent, a pairle Azure between chief an oak tree Proper within a circle of five mullets Gules, a palm tree to dexter and a prickly pear cactus to sinister both of the third. Attached above the shield a wreath Or, upon a grassy field the blockhouse of old Fort Dearborn Proper. Attached below and to the sides of the shield a Gold scroll inscribed "SEMPER PARATUS" in Gold.
The shield is white charged with the pairle which appears on the shield of the city of Chicago, shield and pairle are white and blue, the Infantry colors. The green oak tree is for Forges Wood and the stars represent the five major operations in which the Regiment took part in France. The palm tree recalls Cuban and the cactus the Mexican border service. The crest is that of the Illinois Army National Guard. The motto translates to "Ever Ready."
The distinctive unit insignia was approved on 13 March 1925. It was amended to change the motto to Latin on 16 October 1926. The insignia was rescinded/cancelled on 20 October 1961.