Shortly after the United States entered World War I, the regiment was constituted in the National Army on 18 May 1917, and organized on 3 February 1918 at Camp Stanley, Texas.

It conducted regular equestrian training on the horses of the Valley Forge Military Academy and often participated as a mounted unit in Philadelphia's Army Day parade.

[2] After the United States entered World War II, it was disbanded on 18 October 1943[2] due to most of its officers being called up for active duty.

The distinctive unit insignia included a 1 1/8 in (2.86 cm) gold colored metal and enamel device, which consisted of a yellow shield divided by a black stripe with three plates in the center.

The regimental coat of arms was of a similar design to the distinctive unit insignia but included the Organized Reserve's Minuteman crest above the shield.