This rare Civil War carbine was manufactured by the Cosmopolitan Arms Company of Hamilton, Ohio. The company was owned by E. Gwyn and A.C. Campbell. These carbines were the predecessor of the Gwyn & Campbell "Grape Vine" carbine, manufactured from 1859 to 1862. This carbine is one of only about 50 Early Variant Models with the double loop enclosed lever with the locking latch for the breech inside the loop. The top of the breech block is marked "COSMOPOLITAN ARMS CO." in an arc above "HAMILTON O. U.S. / GROSS' PATENT". The matching serial number appears on the bottom of the barrel and frame at the breech. Mounted with a smooth straight grip stock with an iron buttplate.