Seconding what Shadow said earlier, if you're going to make it to the east coast, try to stop in DC. I lived on the east coast(near Baltimore) for quite a few years, and visiting DC never got old for me. The museums are incredible(and as mentioned, free), the monuments are worth seeing, and there are a ton of fantastic bars and restaurants as well. The metro(subway) system is safe and relatively efficient, so even if you don't want to drive into the heart of DC, it's easy enough to park outside the city, ride in, and just walk around for the day.
Philadelphia is another great city for seeing on foot. Plenty of history, plus the parts that are worth seeing are also safe and clean, making it a great spot for tourists.
Annapolis is a lesser known, but still beautiful city. Gorgeous harbor area. It's also home to the US Naval Academy if you're a military buff at all.
I'd suggest avoiding Baltimore, while the harbor area is nice, if you don't know the city, it's far too easy to end up in places you do not want to be.