By 1851, William Kelly had built Suwanee Furnace two hundred yards northwest, where his experiments perfected his invention of the so-called Bessemer method of making steel, for which he was granted the patent. The blast furnace was a steam-powered, charcoal-fueled brick stack thirty-five feet high with a maximum inner width of ten feet. It made one thousand seven hundred tons of iron in 1857, its last year. Kentucky had been a major iron producer since 1791, ranking third in the U.S. in the 1830s and eleventh in 1965. Charcoal timber, native ore, and limestone supplied material for numerous furnaces producing pig iron, utensils, and munitions in the Hanging Rock, Red River, Between Rivers, Rolling Fork, and Green River regions. The old charcoal furnace era ended because of depletion of ore and timber and the growth of railroads.