A glass vial stopped with a cork during the Civil War has been opened, revealing a coded message to the desperate Confederate commander in Vicksburg on the day the Mississippi city fell to Union forces 147 years ago.

The dispatch offered no hope to doomed Lt. Gen. John C. Pemberton: Reinforcements are not on the way.

The encrypted, 6-line message was dated July 4, 1863, the date of Pemberton's surrender to Union forces led by Ulysses S. Grant, ending the Siege of Vicksburg in what historians say was a turning point midway into the Civil War....