Our big exhibit at the National Museum of American History was the unveiling of the Star-Spangled Banner. The museum had a huge renovation and painstakingly restored the original flag. It's been through a lot between the war, people cutting out chunks for keepsakes, and when we tried to conserve it the first time by sewing a backing, to realizing that was a bad idea and having to remove the backing (one stitch at a time). Now it is housed in a climate controlled area, with just enough light for visitors to view it through glass. It even sits on a flat surface that can be moved inches so it can lay flat and release some of the pressure on the stitches. In it's current condition without any adjustments to our system, it could last another 500-1000 years.
But before we started conserving it, we actually thought it would be a GREAT idea to hang it outside the Smithsonian Castle in 1914. *sigh*