Horace E. Dimick was a gunmaker and 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 sporting style rear sight, and the rifle features a "Rocky Mountain" blade front sight, double set triggers, spurred trigger guard, and smooth stock with pewter cap.

Fair overall with dark gray and brown patina, moderate oxidation/pitting, absent ramrod ferrules, replaced/repaired rear sight with absent elevator, broken hammer screw, one cracked wedge escutcheon, general mild scrapes and dings, and cracks, chips, and divots in the refinished stock. Mechanically fine. If this well weathered St. Louis rifle could talk, what a story it could tell!