Design of the Colt Model 1861 Navy was not unlike Colt's previous "Navy" offering - the Model 1851 Navy - and was essentially a refined version of the strong selling firearm. It featured a curved, single-piece walnut wooden handle with an equally curved trigger system encircled by a brass trigger guard. The hammer was noticeably protruding from the rear of the gun body which was of casehardened metal. The cylinder held up to six rounds of .36 caliber ammunition and did not feature a "bridge" to frame the cylinder within the gun body (as found on the successful line of competing robust Remington brand revolvers). The forward portion of the gun underside contained a webbed contour fitted against the barrel underside, presenting the basic Samuel Colt revolver shape. Sights were noticeable at the front of the gun, above and aft of the muzzle.
A key difference of the Model 1861 Navy over that of the preceding Model 1851 Navy was the use of a 7.5 inch rounded barrel assembly as opposed to the latter's octagonal shaped form. A key difference within the Model 1861 Navy line itself included the use of both fluted and smooth-sided ammunition cylinders (some lacking the typical engraved naval battle scene that gave the lineage its generic identifying moniker of "Navy"). At least 100 of the smooth, non-engraved versions appeared in an early production batch from Colt. The Model 1861 Navy also borrowed some design elements from Colt's other product - the muzzle-loading .44 caliber Model 1860 Army revolver produced from 1860 to 1873 to the tune of over 200,000 examples. Incidentally, both the Model 1851 Navy and the Model 1860 Army shared the same dimensions.
The Model 1861 Navy was chambered for the .36 "Cap and Ball" cartridge (paper cartridges that made use of black powder and a lead bullet - either shaped ball or conical) and operated from the standardized percussion principle that replaced the once-dominant flintlock. As a "single-action" model, the weapon required the operator to manually "cock" the hammer each time before firing. Guns of this Colt family were clearly marked along their left sides with the "Colts Patent" branding engraved text as well as the caliber size (.36), the latter something of a handy visual reference. The loading lever was of the "creeping" style. The gun was relatively small enough and light enough to carry in a holster and a silver plated backstrap was standard to the series. The lightweight nature and operating principles of the Model 1861 Navy allowed the weapon to be fired with some confidence from atop a horse, making it ideal for Union cavalrymen and the like. One variation of the Model 1861 Navy was geared for use with an optional shoulder stock for accurized fire. These were identified by their milled recoil shields and fourth frame screw and produced in 100 examples. Approximately 38,500 of the Model 1861 Navy revolvers were made in all (serial numbers range from 1 to 38,843), manufacture handled by the Colt Patent Firearms Company of Hartford, Connecticut from the period spanning 1861 to 1873. Some made their way to the London Pall Mall Agency and sported iron grip-straps with the barrels marked as "Address Col. Colt London".
The Colt Model 1861 Navy saw usage on the battlefields of the American Civil War and, like the Colt Model 1851 Navy before it, also saw actions in the violent American expansion into the West. This Colt model, however, did not see production numbers to match its predecessor's 250,000 manufactured. Confederate forces actually likened the lighter Model 1861 Navy while the Union's preference was for the Model 1860 Army. The Model 1861 Navy was purchased for use by both the United States Army and Navy. It is thought that less than 3% of original Model 1861 Navy revolvers exist today, making them an extremely rare find for collectors.