there is a good tour you can go on that takes you around the city and shows you all the things that black people have contributed to the city like the art museum and other shit.
the weather is setting in around so it is not really ideal for a day of walking but i have always found all that historic stuff down on independence mall very interesting like the besty ross house and ben franklins house have a lot of hands on stuff you can see and touch, the church where you can go and sit in the pews that the famous people sat in and walk on their graves.
there is also an african american museum very close to the independence mall area. very small but they have some nice exhibits in there
Visitphilly.com gives you the ins and outs of things you can get into.
if your business takes you over near the university of Penn Bobby Flays Burger Palace is a great place for lunch. Burgers are great better than five guys in my opinion and you can get beef chicken or turkey options.
if you find yourself walking or driving past this place and decide to go in i wear a size 13