Exhibit Precedent: National Museum of American History: "The Star Spangled Banner: The Flag That Inspired The National Anthem". Matthew Weikert

http://americanhistory.si.edu/exhibitions/exhibition.cfm?key=38&exkey=70#gallery

I visited this exhibit myself a few weeks ago and the effect they were able to achieve with it is remarkable.  The showcase itself is hidden behind a huge wall, and to protect the flag it is in a very dim room.  The exhibit starts off with pictures, information, some interactive items, and sounds that continue the feeling throughout.  Around a corner you get an amazing look at the flag which has been preserved in a special room behind glass.  After that sight there is an interactive table with tons of information to play with.  The best instance from this exhibit is that from the necessary hiding of the flag a grand surprise element ensues which makes the whole thing stand out from the other exhibits.