The Battle of Kennesaw Mountain was a military engagement between Union forces commanded by Major General William T. Sherman and Confederate forces commanded by General Joseph E. Johnston on June 27, 1864 during the Atlanta Campaign.
Prelude to the Battle
Federal Breakout from Chattanooga
In late November 1863, Union forces commanded by Major General Ulysses S. Grant successfully lifted Confederate General Joseph E. Johnston’s siege of Chattanooga, Tennessee. Union victories at the Battle of Lookout Mountain (November 24) and the Battle of Missionary Ridge (November 25) forced Johnston to withdraw thirty miles south near Dalton, Georgia.
Grant Promoted to Lieutenant General
After the Federal breakout from Chattanooga, President Abraham Lincoln promoted Grant to the special rank of Lieutenant General and placed him in command of all Union armies. Grant moved his headquarters to Washington, leaving his trusted subordinate, Major General William T. Sherman, in command of federal operations in the western theater.
Grant’s Umbrella Strategy
Grant’s primary military strategy was a coordinated effort to attack and defeat the two main Confederate armies in the field, Robert E. Lee and the Army of Northern Virginia in the east, and Joseph E. Johnston and the Army of Tennessee in the west.
On May 5, 1864, Grant launched his Overland Campaign against Lee in Virginia. Two days later, Sherman led three armies, the Army of the Tennessee, commanded by Major General James B. McPherson; the Army of the Ohio, commanded by Major General John M. Schofield; and the Army of the Cumberland, commanded by Major General George H. Thomas, out of Tennessee in pursuit of Johnston’s army in northern Georgia.
Fighting Along the Western and Atlantic Railroad in Georgia
Throughout the summer of 1864, the Confederate and Union armies engaged in a series of battles between Dalton and Atlanta in northern Georgia. Most of the fighting occurred at places on or near the Western and Atlantic Railroad, which connected Chattanooga and Atlanta. Both sides depended on the railway for supplies throughout the campaign. In a pattern that he often repeated, Sherman used flanking movements that threatened the railway to Johnston’s rear, forcing the Confederate commander to retreat south to protect his supply lines.
Sherman Tries to Turn Johnston’s Flank
By June 19, 1864, Johnston had withdrawn the Army of Tennessee to a defensive position astride Kennesaw Mountain near Marietta, Georgia. Initially, Sherman decided that Johnston’s new line was too strong to risk a frontal attack. Instead, he attempted to extend the Union line west and turn Johnston’s left flank. Anticipating Sherman’s plan, Johnston countered by sending reinforcements to bolster his left flank. On June 22, Sherman’s troops defeated the Rebel defenders at the Battle of Kolb’s Farm, but they did not turn the Confederate flank.
Failed Federal Assault Near Kennesaw Mountain
After the Battle of Kolb’s Farm, Sherman concluded that Johnston’s center was vulnerable, believing that the Confederate commander had stretched his line too thin by committing too many soldiers to protect his left flank. Thus, Sherman ordered a major frontal assault on Johnston’s army on June 27. Following an artillery barrage, the Army of the Tennessee attacked Johnston’s right flank while the Army of the Cumberland attacked the center and the Army of the Ohio attacked the left.
Aftermath of the Battle
Each of the attacks against the well-entrenched Confederates proved futile and resulted in heavy Yankee losses. The Union suffered about 3,000 casualties (killed, wounded, captured/missing) compared to Confederate losses of roughly 1,000 soldiers (killed, wounded, captured/missing).
Despite the Rebel victory at the Battle of Kennesaw Mountain, Johnston fell back to a new defensive line (Johnston’s River Line) along the west bank of the Chattahoochee River after the battle.