Too bad on the fold in it. It must be a series 1996. Pretty old note to find.
http://www.uspapermoney.info/serials/f1996_h.htmlI don't know if I would keep it or not. It depends on how bad the fold is and how nice the note looks. It is a lot of money to tie up, if the value doesn't increase above face value, over the long run.
Are you going to keep it?