|The piece of paper was rolled up, tied with string and sealed along with a bullet in a glass vial.|
The full text of the message reads:
'Gen'l Pemberton: You can expect no help from this side of the river. Let Gen'l Johnston know, if possible, when you can attack the same point on the enemy's lines. Inform me also and I will endeavor to make a diversion. I have sent some caps (explosive devices). I subjoin a despatch from General Johnston.'The code is called the 'Vigenere cipher,' a centuries-old encryption in which letters of the alphabet are shifted a set number of places so an 'a' would become a 'd' — essentially, creating words with different letter combinations.
Read more: http://www.dailymail.co.uk/news/article-1341666/CIA-codebreaker-reveals-147-year-old-Civil-War-message-Confederate-desperation.html#ixzz19H4zdu8Q