Value of a 1963 Dollar Bill?

I have a 1963 five-dollar bill from my Grandmother, who told me that it was ‘special’. I was wondering what about this bill makes it important. It appears to be a normal note, but the seal is in red, not green. I know that this has no worth to a collector because of it’s condition, but it has been bugging me lately, since I can’t find any information on it other than an ‘urban legend involving the Kennedy assassination’.

edit; found a picture of it http://en.wikipedia.org/wiki/File:US_$5_1963_USN.jpg