https://www.historicaerials.com/I did a quick search and didn't see this site ever being discussed.
I wanted to share this, because it's a brilliant research tool (and entertainment for old rail nerds) into some of the visual history of the track layouts of the prototype railroads.
Now, it's not perfect, and it doesn't go as far back as we'd all wish, or with as much detail in many places, but it's the best tool I've found for finding actual aerial pictures of historical places, places long gone to the sand of time.
For example, the site has amazing aerials, with pretty good detail, of the Alexandria VA area in 1962. Including the two Railcar builder facilities Alexandria had at the time, the old Southern Yard (now long gone) and the tracks along the Alexandria waterfront on the Potomac. I never thought I'd be able to see such good pics of those things from an aerial perspective, heck, any pics are hard to find sometimes.
So there you go, I hope it provides you the same hours of entertainment, er, "research" it has provided me.
Enjoy.