I am traveling down the East Coast in April, and Im looking for ...?

...Some really cool places to stop and visit. Im leaving from Central Vermont and headed to Washington DC, so I will be passing through a few different states. Anyone have any suggestions of some "must see" places in Mass, Conn, New York, New Jersey, Penn, Upper Delaware %26amp; Washington DC...? Already on the list is: The Mutter Museum, Philadelphia Zoo, The Smithsonian, The Holocaust Museum, Madame Tussauds of DC, The New England Aquarium, and the Boston Duck Tours. Any and all ideas appriciated!! Thanks!I am traveling down the East Coast in April, and Im looking for ...?
I'd visit ground zero in New York.. pay some respect to the lives lost. I was going to mention phili zoo but you already have it so thats good hmm. Also in PA is the shut down State penitentiary which has a lot of history they give tours (if youre into that kind of dark history)I am traveling down the East Coast in April, and Im looking for ...?
The coolest museums in DC are the Air%26amp;Space Museum and the Spy museum. If you like impressionist art you may like the Barnes Museum in Philly--free but you need a reservation. If you like science and space check out the museum of natural history in NYC. Gettysburg if you like history though a bit out of other way of your trip