circa 1870s Map of Pennsylvania from Smull's Handbook.
See mapsofpa.com article
1901 General Map of Bituminous Coal Fields in Pennsylvania by Baird Halberstadt. (Western PA)
scanned courtesy of Penn State Libraries.
Note: a different scan of this map is available
1903 Rand McNally Co.'s Pennsylvania
1918 Steam Railroad Map of Pennsylvania (includes electric railroads)
scanned by Penn State Libraries
Railroad Map of
scanned courtesy of Daniel Van Epps (multimodalways.org)
from a B&W copy.