What a neat trip! I love the Smithsonian -- a person could spend a whole week on the Mall, easily. I always feel like I've just scratched the surface. If I ever got a chance to sublet an apartment for a month or two, I would -- though probably not in midsummer.
Interesting that the protesters were kept to the back of the White House, though not surprising. I remember wandering back there once during the Nixon years and seeing five big buses full of men in riot gear, just waiting. That was unnerving!