 Complete the following phrase:  During the siege of Vicksburg, Confederate General Joseph E. Johnston had gathered a force of 30,000 men in Jackson, Mississippi, with the intention of relieving the garrison under the command of John C. Pemberton that was trapped inside Vicksburg. After Pemberton surrendered to Grant on July 4, Johnston advanced towards the rear of Grants forces. In response to this threat, Grant instructed Sherman to attack Johnston. Sherman conducted the ensuing 