By the 1800s, the iron industry was a major part of the Pennsylvania economy.  The nineteenth century witnessed crucial technological changes, which transformed the industry, and would lead to the United States becoming one of the world’s top steel producers.

Coal and coke replaced charcoal as a source of fuel, which made iron making a more efficient process and increased both production and quality.  The introduction of railroads improved transportation of natural resources and iron goods.  These and other technological changes affected the size of iron works, types of ownership, labor-management relations, and led to the creation of new products.