In this thread:
https://www.therailwire.net/forum/index.php?topic=27570.0Dave posted a link to the USGS site. I was able to download aerial photos from 1950 for all the surrounding areas where I live. I chose to try and model 1948 so this was perfect for me as I could see just what the Erie looked like back then. I was born in 1974 at a hospital in Youngstown, Ohio so I don't recall much from 1950
I knew that Youngstown was wall to wall steel mills, but by the time I was born most of them were all gone. Some time during high school they knocked down the last blast furnace. For the last few days I have been studying the old photos and discovering things I didn't know in every pixel.
Here is one compared shot.
http://binged.it/WPamhdAnyways... these maps are a great resource.