Beginning on May 23, 1863, Vicksburg had been subjected to a terrible siege. Not only did Grant’s army have far more cannon, they also showed no desire to conserve ammunition. On the contrary, they threw everything they had at Vicksburg every day and through much of each night.

Grant was supremely confident of the ultimate result, but even he was at times frustrated by the stubborn defense of the Confederate defenders. Later he learned that General John Pemberton had believed that General Joseph Johnston would come to his aid. Every few days, Pemberton sent out messengers—many of whom got through—asking Johnston when the relief would come. For long periods there was no reply, but when it finally came, Johnston announced he would make a demonstration against Grant on July 8.