Pennsylvania has a rich railroad history, at its peak, back in 1920 it had over 11,000 miles of track and presently, thanks to this source I was able to count about 85 railroad bridges in Pennsylvania, that exist or existed in the last 100 years.
With American steel and iron manufacturers plants in PA, especially the Pittsburgh area, the railroads had a huge economic and landscape impact.
Along with the rail line expansion of the 1910-1920, hundreds of small manufactures started seeing the benefits and drastically improving their day to day business, of a large railroad infrastructure.
Soon after the state has been known not only for steel, coal, coke and lumber but leather, railroad cars, textiles and glass.
Great read for any train fan interested in Pennsylvania's railroad.
Railroad Bridges in PennsylvaniaAs previously mentioned, I was able to count about 85 railroad bridges throughout PA.