Color enhanced illustration of the Siege of Vicksburg in 1863, which was the culmination of the Vicksburg Campaign and a key turning point of the American Civil War. The Confederates had control of the fortress city of Vicksburg, making it a barrier of the Mississippi River for the Union. Union Maj. Gen. Ulysses S. Grant took control of the Mississippi River by launching an assault on the Confederate army of Lt. Gen. John C. Pemberton at Vicksburg. After more than a month of attacks, the Confederates surrendered, splitting the Confederacy in half.