I was curious and for a couple of summers did the same thing, I checked out old photos in the library, copied them, found the same location, and almost invariably there were far more trees today.
There are several reasons for this. The railroads were a great cause of deforestation, and there were alarmist proclimations around 1900 that we were running out of trees. This led to railroads finding substitues, and eventually the automobile and diesel rail engines halted the railroad's over use.
Also, we stopped using wood for cooking and heat, and got connected to the electrical grid. And finally, we have allowed some lands that were in agriculture to go back to forests.
Michigan has been logged over about 3 times but you wouldn’t know it today.
Basically, Uncle Sam bought land and/or took it and planted trees, ie FDR.
1900's etc. private enterprise did a poor job of 'preservation' and we have learned from such mistakes.
Also, various disease[Chestnut blight] wiped out many of our old growth, and other faster growing trees took their place.
I drive by this nearly every day, and one bitter cold, windy February morning, it just struck me as I drove by, so I stopped. It was cold enough that morning with the wind to make my eyes water uncontrollably.
Interesting thing is, there are all these trees and vegetation around there, but an illustration of the area done back around that time (I saw it in a museum here) shows no trees as far as you can see in any direction! It kind of blows your mind to stand there and imagine that...