Shortly after the United States entered World War I, the regiment was constituted on 18 May 1917 in the National Army, and organized in February 1918 at Camp Del Rio, Texas.

[2] After the Attack on Pearl Harbor resulted in the American entry into World War II, it was converted into the 65th Tank Destroyer Battalion on 30 January 1942.

The distinctive unit insignia included a 1 1/8 in (2.86 cm) gold colored metal and enamel device, which consisted of a shield with a red cross with a yellow star in the center, and a red and gold scroll below the shield, which was inscribed with the regimental motto, "Perseverandum".

The shield symbolized the United States Cavalry, the cross, similar to that on the colonial seal of Virginia, represented the unit's Virginia assignment, the red symbolized its World War I field artillery service, and the star represented service in Texas.

The 307th's coat of arms was similar to the distinctive unit insignia except that it added the Organized Reserve crest, a Minuteman, and omitted the motto.