Early American Iron Smelting
Early American iron ore was smelted all over the country using ancient methods. Iron was necessary when blacksmiths were essential to everyday life.
Everyone has seen pictures of the noble blacksmith in pictures of Early American life. The smith, a mighty man, pounds away on his iron horseshoes and makes wonderful things out of iron for the kitchen and the farm, but it wasn't until recently that people started to ask where this iron came from that so many smiths worked for so many decades.
The history of early American smelting operations has been hard to find because, while America consisted of British colonies, it was illegal to make a product which could be imported from the mother country. The British, especialy those in the iron producing Midlands, wanted to export pig iron to the colonies, but it was heavy and the long distances involved made it expensive.
Despite the British ban on home manufacturing, many American blacksmiths got involved in secretly locating bog iron or iron ore, and began smelting their own pig iron. All over the country, there are outcroppings of rock laden with iron ore. That's easy to find.
Even where iron outcroppings do not come to the surface, people on long wooden sleds fished iron out of bogs where the chemical action of artetian water joined with surface oxygen to precipitate crude iron. Bog iron formed in irregular shaped balls that floated beneath the bog's surface.
Today we picture smelters as giant contraptions spewing sparks hundreds of feet, but in colonial America a tiny smelter could be made no bigger than some backyard barbeque pits. The fundamental design required a chimney into which fuel could be poured, holes along the side to allow air into the fire box, and spickets at the bottom which could be opened up to draw off the molten iron into pre-made pathways in sand where pigs could be formed.
To start the burn, a smelter required large amounts of charcoal -- made from burning wood into briquettes -- some crushed lime, and a large quantity of sorted raw iron ore. These fires would go on for several days sometimes and result in hundreds of rough iron bars, mysteriously known as pigs since medieval times.
These pigs contained iron which was adequate for cast iron, but if black iron was needed, such as that used by blacksmiths, then a trip hammer mill was required where the pig could be heated and repeatedly pounded until the carbon balance in the iron made it pliable enough to be worked in one of the colonys' hundreds of blacksmith's shops.