Around 4,000 of these Type II carbines were manufactured by Gwyn & Campbell in Hamilton, Ohio. There were also three variations within these Type IIs, and this example is the second variation (1,370 produced) with slightly different buttplate curvature and the vertical lever catch. The design is substantially the same as the earlier Cosmopolitan carbines manufactured before Cosmopolitan changed names to Gwyn & Campbell. Both firms operated in the same plants and were owned by Edward Gwyn and Abner C. Campbell. The design is based on improved designs by Gwyn based on Henry Gross' designs, his former partner. This example has a pyramidal front sight, notch and folding ladder rear sight, "A & CO" on the bottom of the barrel, "UNION/RIFLE" on the right side of the frame, "GWYN & CAMPBELL/PATENT/1862/HAMILTON O." on the lock plate, a boxed "WHR" cartouche on the left stock flat and matching serial numbers.