Growing up in Pennsylvania and visiting upstate New York a lot to see relatives in the late 50's and 60's (I was born in 1953) I never saw a bald eagle. When I moved to Montana at age 15, I say bald eagles, in fact, I saw several hundred that congregate each fall in the area between Canyon Ferry Reservoir and Hauser Dam just outside of Helena, MT.
I've also seen many golden eagles, which are bigger than the bald eagle, in Montana. Their favarite food is Rocky Mountain ground squirrel.
Now I get to see them from November on into April on the Skagit (my home river in the winter since I live in the Skagit Valley). There is still nothing quite like seeing one of these very majestic birds. I've seen as many as 35 of them on a gravel bar on the opposite side of the river from me, some perched, some eating salmon carcasses, some simply standing on the beach.
The banning a DDT has allowed these great birds to return to their historic range and reestablish viable populations. The DDT used to make their egg shells both thin and brittle. This caused the eaglets to never become hatchlings because the egg shells would bread before they were developed beyong the embyo. Now 35 years after DDT use was banned in the U.S. and Canada, the bald eagle has returned. Sure took a long time to get sufficient amounts of DDT out of the environment to allow this to happen.