Henry O. Peabody of Boston, Massachusetts patented a new breech-loading, downward- tilting, lever-operated action for a long gun. The patent was awarded on July 22nd, 1862 during which time the American Civil War (1861-1865) raged on. The action was produced in both rifle and compact carbine forms and in differing calibers - .45 Peabody rimfire, .45-70 Government, .50 rimfire, 50-70, .433 Spanish and 10.4mm Swiss rimfire. Overall design of the firearm was conventional with a long-running, single-piece wooden body, a single barrel band joining barrel and frame and an integral grip and shoulder stock arrangement. The action was of the percussion principle requiring use of percussion caps to actuate a powder charge and send the bullet out of the muzzle. Barrels were rifled for accuracy and range, a far cry from the smoothbore designs of old. A bayonet was optionally affixed under the muzzle in the usual infantry-minded way.
A carbine form based on the Peabody action was entering development during the latter stages of the Civil War. While a rifle form was, in fact, trialed by the US Army during the conflict, it was not adopted due to teething issues and the, ultimately, end of the war in 1865. Likewise, the carbine did not achieve status prior to the end and, instead, found more success through export. Manufacture of the Model 1866 Carbine was handled through the Peabody and Providence Tool Company of Providence, Rhode Island USA. The primary caliber was .50 rimfire though the aforementioned bullet forms were also in play due to the non-standardized world landscape - particularly in Europe. Barrels measured a handy 20-inches long and loading was through the breech as opposed to down the muzzle.
A few American states eventually purchased the type (Connecticut, Massachusetts and South Carolina) during the post war years primary centering during the 1870s). France, however, ordered some 33,000 of the rifle and they were then joined by Switzerland, Spain, Mexico, Romania and Canada in the purchase of thousands more. Overall, some 112,000 Peabody Carbines found circulation in the United States, Central America and throughout Europe.