While in Philadelphia my dad and I visited "old town," which is where all the historical houses and such are located. We visited the Liberty Bell, Congress Hall, Independence Hall, and some of Ben Franklin's old haunts.
Here's the Liberty Bell (of course). We stood in line forever to see this and even had to have our bags searched by security... Although, I kind of doubt the likelihood of anyone trying to attack the Liberty Bell Center. Maybe I'm just naive.
Here is where the first official senate was held in the temporary capital of Philadelphia. Most of the furniture is reproduction, but some of the chairs are original, which is pretty vintage if you ask me.