We told you yesterday about the big donation of objects from The X-Files to the same Smithsonian museum here in Washington that keeps The Fonz's leather jacket and Dorothy's ruby red slippers.  What we didn’t tell you about was the  thrill our intern Lisa Gartner got as she was led through the very popular, very interesting and very closed-for-renovation National Museum of American History. Millions of tourists denied entrance  during a two-year renovation would love to see what Lisa saw after entering through a sneaky staff entrance in the underground garage of the museum.  "One moment I was looking at a model of the first automobile; the next I was discovering electricity," Lisa says.  "In a dim room, the first people to ever cross the United States are draped with plastic furniture covers. The whole place is dark, but clean and spacious, and the reopening in the fall will be exciting. Look for new architectural features and a state-of-the-art gallery for the famous Star-Spangled Banner, the original flag that inspired the National Anthem."