Extremely Rare Six-Gallon Stoneware Jar with Freehand Cobalt Decoration, Stamped "N. COOPER & POWER / MAYSVILLE" and "HAMILTON / Greensboro, PA," circa 1860, cylindrical jar with incised banding around midsection, tooled shoulder, semi-rounded rim, and applied lug handles. Decorated with a finely-brushed looping vine design across the shoulder, a second vine at the midsection, freehand stripes throughout, and a freehand "6" flanked by dashes at the base. Reverse features both the impressed merchant mark, "N. COOPER & POWER / MAYSVILLE," as well as the impressed maker's mark, "HAMILTON / Greensboro / PA". This jar is the only example of Western Pennsylvania stoneware made for the Kentucky market that we have seen bearing this extremely rare "double stamp". An exceptional example, and important for the attribution of other jars. Provenance: A fresh-to-the-market example from a forty-year Southern U.S. collection. Excellent condition, the reverse with a small rim chip and minor rim nick, the interior of the rim with a small chip and two tiny nicks.