East coast travel

Hello! I am planning on traveling down the East coast starting in Maine. I will be traveling through Vermont, New Hampshire, Rhode Island, New Jersey, Delaware, Massachusetts, New York, Pennsylvania, and Connecticut (not in that order) I am looking for ideas of places to visit or things to see that are not well known. Please comment the state and what you would suggest (I am not planning on spending much time in New York. Maybe just driving through).

Also, what time of year is best to travel down the East coast?

One of the things I really want to see is Amish Country in Lancaster.

Thank you!