It was converted into a tank destroyer battalion after the United States entered World War II.

[3] After the United States entered World War II, the regiment was converted into the 75th Tank Destroyer Battalion on 30 January 1942.

[3] The following officers commanded the 324th:[3] The regimental coat of arms and distinctive unit insignia were approved on 16 April 1929, and both were rescinded on 26 February 1959.

The distinctive unit insignia consisted of a gold colored metal and enamel device 1 1/16 (2.70 cm) in height with a blue shield and a yellow border.

The coat of arms was of a similar design except that it omitted the motto and included the Organized Reserve Minuteman crest above the shield.