That is a neat site. I'd recommend just downloading Google Earth though. At least for our land, it has all of the same images and an easier interface without the nasty watermarks.
I'm not sure if Google Earth goes all the way back to the 50s though. That's super impressive. Any chance we could convince you to show a side by side?
I think a lot of states may have historical sites where you can look up old aerial photos. I have some great pics from 1938 for areas around my land and have looked up in other parts of the state for places where family has land and I've hunted. Think they did it for areas where you could see farms and signs of people living, not counties with very sparse populations back then. Of course black/white photo but the site allowed you the option to download a really detailed pic with the file being over 22 MB.
I expect some of this was being driven by all the public works projects happening during the Depression at least that is a guess. The file has great detail when digitized but you can tell where the picture was spliced together with a patchwork of individual pictures to make a bigger view.
Edit: Had to dig back in my notes but this is link to WI Historical Aerial Image Finder. Assume other states may have similar http://maps.sco.wisc.edu/WHAIFinder/#
Google earth only goes back to 1985 on mine,I am looking for a oil field photo where my farm is now.I was a big oil field starting around 1926.Had a couple well bringing in over 1000 barrels a day.
There's never been sufficient money allocated at the federal level to digitize all of what's been collected on film. Some states / state agencies have taken the initiative to at least scan the hardcopy imagery from the past. Pennsylvania and Penn State provide a rich digital collection although most of it is not geo-rectified. https://datacommons.maps.arcgis.com/apps/View/index.html?appid=10af5f75f9f94f01866359ba398cb6a9
I am mostly familiar with the imagery collected by USDA's Farm Service agency. Aerial photography for farm conservation planning purposes started in the late 1930s and was related to the first "Farm Bill" passed in the early 1930's in response to low farm prices and the Dust Bowl.
Those are cool sites.
Mortenson posted up a similar cool link a few years ago I think Vintage Aerials, I was able to find a sweet pic of the old homestead on our farm from 1968.
Here a great free one for Wisconsin - 1938 fly over of the entire state - huge black and white data base with a bigilian images. Worth the look for us Cheeseheads. Really good imagery with current layover images to go back and forth with.
I got lost in this rabbit hole last night and found this thread after the fact. Very cool to see what they did decades ago. My thick timbered home lot was completely bare in the 50s and my hunting land had much more cleared as well. MN's site is great for this.
My property was one of the top producing oil fields in kansas at one time and there were shanties and derricks all over it.I wish I could find a picture of that.