In the heat of the Civil War, Abraham Lincoln famously proclaimed, "Vicksburg is the key." The key to the heart of the Confederacy, the key to control over the mighty Mississippi River, and ultimately, the key to the Union victory. Vicksburg, perched on a bluff overlooking the river, was an unassailable fortress in the eyes of the Confederacy - their "Gibraltar." Yet, the very strength of Vicksburg became its weakness as it drew the unerring focus of Union General Ulysses S. Grant.