The Cosmopolitan Carbine was a percussion-based carbine firearm produced out of the Cosmopolitan Arms Company facility for the Union Army during the American Civil War. The concern was owned by Edward Gwyn and Abner C. Campbell and based in Hamilton, Ohio. Most of these carbines were issued to the 5th and 6th Illinois Cavalry units with only about 1,140 examples ever placed into circulation, making her an extremely rare collector's breed today.
Outwardly, the Cosmopolitan Carbine held a rather unique design shape especially considering the shapely "double-loop" enclosed lever. Early-batch production models (numbered roughly 50 or so examples) held the locking latch for the breech inside this loop. The latch allowed access to the breech by a pivot that exposed the chamber to accept a fresh cartridge. The wooden body (made of walnut) was curved with an elegant contour and integrated the straight hand grip and shoulder stock for a firm two-handed hold when firing. The barrel was visibly half the length of the weapon and octagonal in shape with a flip-up type rear sight as well as a front post. Optional open loops under the barrel and the stock allowed the use of shoulder slings, a convenience for the soldier on horseback. The carbine was chambered for the .52 cartridge and loaded through the breech as opposed to the muzzle of similar percussion musket firearms. The hammer was set to the right hand side of the receiver for quick access. The buttplate at the end of the stock was iron. Barrel length for the weapons ranged from 19 inches to 22 inches with a blue finish. The guns were stamped with "Cosmopolitan Arms Co." written over the words "Hamilton O. U.S. / Gross Patent", thusly their origins being clearly marked and identified.
The US Ordnance Department placed an order for Cosmopolitans in December of 1861 with deliveries beginning in July of 1862. As mentioned above, the carbines appeared heavily with the 5th and 6th Illinois Cavalry regiments and, coupled with the 2nd Iowa Cavalry regiment, were fielded in anger during the 1863 raids on Confederate forces in Southern territories. The attacks became known as "Grierson's Raid" after its commander Colonel Benjamin Grierson. His 1,700 strong contingent traveled from hostile lands in Tennessee through Mississippi and into Louisiana, wreaking havoc against targets of opportunity with complete aggression while amazingly minimizing their own losses. The Cosmopolitans no doubt played a role in the ensuing successes. The raids occurred from April 17th to May 2nd, 1863 during the Vicksburg Campaign that eventually led to Union control of the vital Mississippi River artery.
Gwyn and Campbell then went on to produce the Gwyn & Campbell "Grape Vine" Carbine (also known as the "Union Carbine") beginning in 1859 and spanning into 1862. This carbine succeeded the Cosmopolitan as well as being produced in the same factory and, like the Cosmopolitan before it, went on to see widespread use with Union Cavalry regiments.