These factors all allowed Pittsburgh to become the major American city contributing to the Industrial Revolution, and Pittsburgh's connections with the rest of the United States helped to spawn the Industrial Revolution in other parts of the country.
In order to understand why Pittsburgh was such a key player in America's Industrial Revolution, one must trace the city's boom back to the start of the Industrial Revolution within the city's own boundaries. The start of the Industrial Revolution in Pittsburgh can be traced all the way back to the start of the nineteenth century. The low cost of coke, and iron, alongside the large amount of coal found near Pittsburgh contributed to the development of the iron industry within the city, and later, within America (Bernal, 1970, p. 83). Most of the iron production during this time period used charcoal as a source of fuel. However, the discovery of the abundance of minerals around Pittsburgh introduced a new and better way to produce iron. This occurred mainly because coal can create a higher temperature, and is thus more effective for burning in comparison to charcoal. Furthermore, the coal found outside of Pittsburgh was excellent in quality, and was vary abundant (Derry and Williams, 1993, p. 94). For example, coal seams were discovered to be at least four to ten feet in thickness outside the city, and when compared to London, Pittsburgh's coal turned out to be of better quality, more abundant, and most importantly, more profitable. The early production of iron nails, balls, and different farm tools began to occur, and eventually these products were widely available to the public. In 1812, Pittsburgh developed the first iron rolling mill, using the development of the steam engine. This first mill spawned many other mills using steam engine power, and the city grew as a result (Hannegan, 2000, p. 23). By 1815, Pittsburgh could be called the biggest city in the east. This advancement in iron technology in the city opened the door to allowing Pittsburgh to become a major city within the Industrial Revolution. Obviously having better quality coal than London, which was at the heart of the Western Industrial Revolution, is an early indicator of how important Pittsburgh was becoming to the rest of the United States. The coal developments in Pittsburgh inspired the rest of the United States to revise its approach to goal development.
After the development of the iron mills came the development of glass factories, pottery mills, breweries, grist mills, nail mills, steam engine factories, cotton factors, and printing offices. The glass factories were yet another important development to the Industrial Revolution and the rest of the United States.
Not surprsingly, plate glass saw very limited residential use in the 1800's. In Boston some of the wealthiest people had begun to use polished plate glass instead of sheet glass in their front windows before 1850. In 1897 the Marsh Plate Glass Company developed a continuous lehr (oven) for annealing plate glass, reducing the carefully controlled cooling time from three days to three hours. Oldhousejournal online