He actually became colonel after Colonel Jeans resigned in August, 1863. He effectively left the regiment to command the Iron Brigade when Price raided into Missouri in the fall of 1864.

Colonels (2nd/12th Missouri Cavalry Regiment): Upton Hays, killed ca. September 18, 1862; Beal G. Jeans, resigned prior to August 20, 1863; David Shanks,promoted to colonel August 20, 1863; wounded and made prisoner October 6, 1864, while forcing a crossing of the Osage River east of Jefferson City.