Gwyn & Campbell manufactured around 8,200 of Type I and Type II carbines in 1863 and 1864, and the carbines were primarily issued to a variety of Midwestern units during the Civil War. This one has the standard Type II markings and features. Matching serial numbers are visible on the bottom of the barrel, frame, and breechblock. A boxed script "WHR" cartouche is on the left side of the wrist, and small "WHR" inspection initials are on the top of the stock ahead of the buttplate tang. There are also some "R" inspection marks on various components. The right side of the frame has "UNION/RIFLE", and the lock plate has "GWYN & CAMPBELL" in an arch over "PATENT/1862/HAMILTON. O".