Briefly: I live about 13km from the Smithsonian's Udvar-Hazy Center on the grounds of Dulles International Airport. I was there when Discovery arrived and I got this picture. I was also there when they rolled it in nose-to-nose with Enterprise, which it replaced.
I heard John Glenn speak at the dedication, castigating the government for retiring the shuttle fleet; he said they should all still be flying.
Discovery now resides in its own hangar, surrounded by relics of other bygone space triumphs. NASA detoxified it, but otherwise did no clean-up at all. It's scuffed, stained and worn, exactly as it was at the end of its last flight; it looks like it could have landed an hour ago. I visit it all the time.