The Model 1866 was essentially a Henry Rifle with improvements invented and patented by Winchester shop Superintendent Nelson King in 1866. The side loading gate, modified magazine and new walnut forearm eliminated the primary defects in the Henry rifle and created the lever action rifle associated with the name "Winchester". This Model 1866 rifle was manufactured in 1869 and features the desirable early production barrel legend: "HENRY'S-PATENT-OCT. 16. 1860/KING'S-PATENT-MARCH 29. 1866". The full serial number "20592" is stamped behind the trigger. The partial serial number "0592" is stamped on the stock inlet and "592" is stamped on the buttplate. The rifle is fitted with a dovetail blade front sight, a folding ladder rear sight, and a single upper tang screw. Sling swivels are attached to the underside of the forend cap and stock. The stock is fitted with a trapdoor buttplate. Includes a single segment to the four piece cleaning rod. The '66 secured Winchester's place in the annals of the West and launched a long line of successful Winchester lever actions that remain popular to this day and still retain the basic form of the '66. It was one of the earliest and most widely used repeating rifles in the American West and saw use in conflicts over land, gold, and other resources on the frontier in the second half of the 19th century in the hands of settlers, Native Americans, outlaws, lawmen, and hunters.

Very good displaying authentic use. The period refinished barrel and magazine tube have a pleasing smooth dark brown patina with areas of spotting associated with being in a challenging environment. The brass has an attractive appearance. The receiver has tight fitting side plates. The wood shows similar working gun character with a couple stress lines on the wrist at the receiver (left side) and a forearm worn from a lifetime spent in the hand. Mechanically excellent. A desirable Henry's patent marked Winchester Model 1866 lever action rifle with a story or two to tell.