The Atlanta Campaign (7 May-2 September 1864) was a series of battles fought in northwestern Georgia and around Atlanta during the American Civil War. In May 1864, following the Union victory at Chattanooga, William T. Sherman and the Union's Western armies were sent by general-in-chief Ulysses S. Grant to apply pressure against the Confederacy in several coordinated offensives. While Grant launched his Overland Campaign into Virginia and Nathaniel P. Banks attempted to capture Mobile in Alabama, Sherman struck from Chattanooga ("the Gateway to the South") into Georgia and the Confederate heartland.
At first, Sherman's armies had a combined strength of 98,500 soldiers, while Johnston had 50,000. However, Sherman's ranks were initially depleted by soldiers on holiday, while Johnston received 15,000 reinforcements from Alabama. Johnston's Army of Tennessee withdrew toward Atlanta in the face of successive flanking maneuvers by Sherman's army group, withdrawing after being outflanked at Rocky Face Ridge on 13 May and at Resaca on 15 May. From 25 to 26 May, the two armies fought to a draw at New Hope Church, where Joseph Hooker's XX Corps was severely mauled. On 28 May, the two sides met again at Dallas, and Sherman would outflank Johnston again on 5 June. The Confederates repulsed a Union attack at Pickett's Mill on 27 May, From 9 June to 3 July, the two sides met again at Marietta, and the Union attacks on Kenneaw Mountain were held off until an outflanking maneuver forced Johnson to withdraw; Confederate general Leonidas Polk was lost in the battle. In July, President Jefferson Davis replaced the overly-cautious Johnston with John Bell Hood, who launched unsuccessful attacks against the Union army at Peachtree Creek. On 22 July, in the Battle of Atlanta, the Confederates attempted to break the Union siege of Atlanta, which was inflicting heavy damage upon the city. The Confederates suffered heavy losses during their failed attacks, and the Union forces were victorious at Ezra Church on 28 July; however, they suffered heavy losses at Utoy Creek on 5-7 August while attacking fortified Confederate positions. The Confederate general Joseph Wheeler attempted to slow the Union advance by raiding Union supply lines from north Georgia to east Tennessee, being forced to withdraw at Dalton on 15 August, and Union general Judson Kilpatrick raided Confederate supply lines at Lovejoy's Station on 20 August, destroying the tracks (which were repaired two days later). From 31 August to 1 September, the final battle of the campaign was fought at Jonesborough, where Sherman attempted to cut off Hood's supply lines to force the evacuation of Atlanta. Sherman cut Hood's supply line but failed to destroy William J. Hardee's command, but the defeat was enough to convince Hood to evacuate the city. On 1 September, Hood evacuated Atlanta and destroyed 81 rail cars filled with ammunition and supplies. On 2 September, Henry W. Slocum's Union troops occupied Atlanta, and the capture of Atlanta boosted Union morale and led to the re-election of President Abraham Lincoln.