Serving in the state guard command, the 6th Iowa Cavalry was dispatched to Camp Cook in the Dakota Territory, in March 1863. In April 1863, Lieutenant Colonel Pollock was sent with two battalions in relief to Fort Randall.
There in September 1863, his corps repelled hostile Indians at the Battle of White Stone Hill. In 1864, he was promoted Colonel in command of the 6th Iowa Cavalry, serving as primarily security against Confederate and Indian attacks to settlers in the Dakota Territory until the end of the war.
For meritorious services, he was brevetted Brigadier General of US Volunteers on March 13, 1865. CDV is about 4" x 2.5". Overall in Good or better antique condition with some stains, aging, etc.