Horace E. Dimick was a gunmaker and gun dealer in St. Louis, Missouri, from 1849 into the early 1870s and ran a "Western Emporium" where he sold a variety of goods. Dimick furnished 150 rifles of his design and a variety of those made by many other western gunsmiths to what became 66th Illinois Volunteer Infantry under Col. J.W. Birge during the Civil War. The unit was known as Birge's Western Sharpshooters and was composed of men from many states. General Fremont reportedly required all recruits for this unit to "fire a three-shot group, not exceeding three inches, at 200 yards with open sights." "H. E. DIMICK ST. LOUIS" is marked ahead of the rear sight, and the rifle features a dovetailed German silver blade front sight, adjustable sporting notch rear sight, double set triggers, spurred trigger guard, and smooth stock.

Fair with gray and brown patina, some generally mild pitting, spots of touch ups, nickel plated forend cap and wedge escutcheons, tool marks, crack in the left rear escutcheon, some replaced screws, multiple cracks in the refinished stock, and general moderate wear. Mechanically fine (no half-cock).