From his base in Acworth, Sherman slowly pushed the Rebel Army back towards Marietta. On June 14, General Leonidas Polk was killed by an artillery shell fired under the personal direction of Sherman. Although Polk was not a great military leader he was beloved by his men and respected by both Johnston and Hood, whom he had baptized during the campaign.
On June 18 the Confederate line ran north to south from Kennesaw Mountain to Peter Kolb's farm. The Union line was less than a mile west.
A frontal assault on Johnston's entrenched position would be expensive in terms of lives. Sherman decided to try the flanking movement that had worked so well further north. Sensing the movement, Hood attacked Hooker's XX Corps in the vicinity of Kolb's (or Culp's) Farm without orders on June 22 (Battle of Kolb's Farm). The move prevented Sherman from turning the Rebel flank, but the 1,000 Confederate dead was an exceeding high cost.
For 5 days the Union Army organized under the watchful eyes of the Confederates. Supply wagons and men stretched as far the eye could see. On Monday, June 27, 1864, Sherman launched The Battle of Kennesaw Mountain, a full frontal attack on the entrenched Rebel line. It would be the worst defeat of the Federal forces during the Atlanta Campaign.
Further Union Army movement after the battle finally exposed Johnston's flank. During the night of July 1-2 the Confederate commander withdrew to fortified positions between Marietta and Atlanta known as the Chattahoochee River Line. The battles for Kennesaw were over. Now Sherman turned his attention to Atlanta.