From perpendicular angel knowledgebase
- Chicago and North Western Transportation Company (Wikipedia)
- Collection: Railroad Maps, 1828 to 1900 (Library of Congress)
- Railroad and post office map of Minnesota and Wisconsin. (Library of Congress)
Note differentiation between railroads in Pennsylvania and The Pennsylvania Railroad.
- Map of the Pennsylvania Railroad, 1918 (as compared to railroads in Pennsylvania)
- Pennsylvania Railroad (Wikipedia) (the system, not the state)
- Rail road map of Pennsylvania published by the Department of Internal Affairs of Pennsylvania, 1895. (Library of Congress)