History of anthracite coal mining in Pennsylvania railroad system made transporting the anthracite exponentially easier, and by the 1860s anthracite coal was regularly supplying urban centers like Philadelphia and New York City and was helping to fuel the American Industrial Revolution. Anthracite and bituminous coal were formed in the eastern and western regions of Pennsylvania respectively during the Pennsylvanian time in the Carboniferous Geological Period (“History of Anthracite Coal Mining”). The Pennsylvania Anthracite Region is in the Valley and Ridge Province of the Appalachian Mountains, with the coal located in the folded and faulted terrain of the Province. The anthracite fields are maintained in synclinal basins that
Anthracite difficulty of igniting it. This was a particular concern in smelting iron using a blast furnace. With the invention of hot blast in 1828, which used waste heat to preheat combustion air, anthracite became a preferred fuel, accounting for 45% of US pig iron production within 15 years. Anthracite for iron smelting was later displaced by coke. From the late 19th century until the 1950s, anthracite was the most popular fuel for heating homes and other buildings in the northern US, until it was supplanted by oil-burning systems and more recently natural gas systems. Many large public buildings, such as