Only an estimate 300 Jenks carbines were altered by James H. Merrill to the Merrill system for the U.S. Navy in the late 1850s to 1860. The Merrill system proved to be more useful in battle due to its ability to be loaded with paper cartridges while William Jenks' system required loading with loose powder and ball. It has a blade front sight on the upper barrel band, combination folding leaf and breech catch rear sight, the two-line Merrill patent marking on the breech, the serial number on the underside of the breech lever, and the original Jenks and Navy markings on the breech end of the barrel under the breech lever including the year "1845."

Good with mostly brown and artificial gray patina, light pitting and spotting, aged patina on the brass and general minor marks. The refinished stock is also good with small dents and scratches and mostly smooth oiled finish. Mechanically fine.