That's an awesome trip! It is a great thing to physically see locations of the history of this country. You can learn anything you want from the internet (less so now but books as well) but to actually see and soak in the atmosphere is something everyone should experience
Our jr class trip in high school was to DC, it was about 18 months after 9/11 and we still got a tour of the Pentagon, supposed to be the White House but I believe it wasn't having tours yet. We also went to Arlington, where I almost received detention for "wandering off", but was because I wanted to go to my great uncle's grave. After hearing that I was told I should have let someone know and got out of it. We also spend time with the cherry blossoms, at all the War Memorials, and Lincoln Memorial. We only had so much time for a day trip but you can really pack it in with everything so close.
Next stop on your historical trips should be Philadelphia, when you get a chance. I take it for granted how much history is around here but seeing actual homes, roads, and building that are 250 years old is really eye opening. If you have a car rental, Valley Forge isn't far away either. Of course if anyone comes here, I can point you in the right direction for food, or under the radar sights.
