A retired CIA codebreaker deciphered a 147-year-old message sent to Confederate Lt. Gen. John Pemberton while he was defending against Gen. Ulysses S. Grant's siege of Vicksburg. It reads, "JP - Kind of reconsidering this whole 'secession' thing. Sry! Peace."
Kidding! Totally kidding. According to John Gaddy, the codebreaker, the message reads "You can expect no help from this side of the river"—thought to be sent by Maj. Gen. John Walker in response to request for help. So, maybe for the best that it never reached Pemberton.
In fact, the message was dated July 4, 1863, the same day Pemberton surrendered, after a six-week siege that left Vicksburg so sore they supposedly refused to celebrate Independence Day until after WWII (in the immortal words of General Grant: "U mad, Vicksburg"). So it would have been really extra useless to poor Pemberton!
The message was sent in the small bottle you see above, weighted down with a bullet, possibly so it would have sunk in the river if discarded by a messenger. It had been in the Museum of the Confederacy for over a century before it was opened; and was originally thought to be a random collection of letters. Gaddy took a few weeks to decipher the code—"the Vigenere cipher, which involves shifting letters of the alphabet a set number of places." Maybe for his next project he can decipher why Southerners are so hung up on a war they started to defend what might be the single most despicable institution in the history of the world, and then lost!