Then we walked to the National Museum of American History, to see their coin collection, which is a hobby of Mark's. unfortunately, only a fraction of the collection is on display, because the building is being renovated. But we did see their most renowned items -- they picked and chose the top attractions for people to see.
They also had a display of the First Ladies' gowns, and various china patterns used in the White House. So we did get to see SOME interesting things there.
Now, after having gotten plenty of exercise walking around DC, we're headed back. Yep. It was a great day. :-)