The DDT made the egg shells very breakable, so that there were no new bald eagles able to hatch from them. There has also been some hunting and poaching. It is now a felony to shoot an eagle. No one may even own a part of an eagle, like a feather or a foot without a State and Federal permit. There are many protected areas for nesting Bald Eagles in the United States.
People are to stay away from their nesting areas.
Man-made reservoirs, like the one at Patoka Lake, are giving the Bald Eagles a chance to nest again. Many states have their own plans on how to save the Bald Eagle.