Acadia is my favorite park in the eastern US. Lakes, mountains, and the ocean all in one place. If you're into biking, there are miles and miles of carriage roads that were built around 80 to 100 years ago. One can rent bikes out of Bar Harbor and ride through miles of scenery. Wide, not technical, and no car traffic. We saw quite young children on some of the trails. Take a picnic lunch. Plenty of hiking trails, too.
An interesting road through the White Mountains is the Kancamagus Hwy. Road guide
here. Interesting hikes along this road. Some scenic NFS CG's also.
Since it's a fair distance from Indiana to Acadia, I'd pick a route that stays away from the major cities (and traffic). One can get hung up in some monstrous traffic jams at the wrong time of day.