Main Western Theater of The American Civil War - Atlanta Campaign (May–September 1864)

Atlanta Campaign (May–September 1864)

In March 1864, Grant was promoted to lieutenant general and went east to assume command of all the Union armies. Sherman succeeded him in command of the Military Division of the Mississippi. Grant devised a strategy for simultaneous advances across the Confederacy. It was intended to destroy or fix Robert E. Lee's army in Virginia with three major thrusts (under Meade, Butler, and Sigel) launched in the direction of Richmond and in the Shenandoah Valley; capture Mobile with an army under Nathaniel Banks; and destroy Johnston's army while driving toward Atlanta. Most of the initiatives failed: Butler became bogged down in the Bermuda Hundred Campaign; Sigel was quickly defeated in the valley; Banks became occupied in the ill-fated Red River Campaign; Meade and Grant experienced many setbacks and much bloodshed in the Overland Campaign before finally settling down to a siege of Petersburg. Sherman's Atlanta Campaign was more successful.

At the start of the campaign, Sherman's Military Division of the Mississippi consisted of three armies: James B. McPherson's Army of the Tennessee (Sherman's old army under Grant), John M. Schofield's Army of the Ohio, and George H. Thomas's Army of the Cumberland. Opposing him was the Confederate Army of Tennessee, commanded by Joseph E. Johnston. Sherman outnumbered Johnston 98,000 to 50,000, but his ranks were depleted by many furloughed soldiers, and Johnston received 15,000 reinforcements from Alabama in April.

The campaign opened with several battles in May and June 1864 as Sherman pressed Johnston southeast through mountainous terrain. Sherman avoided frontal assaults against most of Johnston's positions, instead maneuvering in flanking marches around the Confederate defenses. When Sherman flanked the defensive lines (almost exclusively around Johnston's left flank), Johnston would retreat to another prepared position. The Battle of Kennesaw Mountain (June 27) was a notable exception, in which Sherman attempted a frontal assault, against the advice of his subordinates, and suffered significant losses, losing 7,000 men versus 700 for Johnston. Both armies took advantage of the railroads as supply lines, with Johnston shortening his supply lines as he drew closer to Atlanta, and Sherman lengthening his own. However, Davis was becoming frustrated with Johnston, who he viewed was needlessly losing territory and was refusing to counterattack or even discuss his plans with Davis.

Just before the Battle of Peachtree Creek (July 20) in the outskirts of Atlanta, Jefferson Davis lost patience with Johnston's strategy and, fearing that Johnston would give up Atlanta without a battle, replaced him with the more aggressive Lt. Gen. John Bell Hood. Over the next six weeks, Hood would repeatedly attempt to attack a portion of Sherman's force which seemed isolated from the main body; each attack failed, often with heavy casualties for the Confederate army. Sherman eventually cut Hood's supply lines from the south. Knowing that he was trapped, Hood evacuated Atlanta on the night of September 1, burning military supplies and installations, causing a great conflagration in the city.

Coincident with Sherman's triumph in Atlanta, Admiral David Farragut won the decisive naval Battle of Mobile Bay on August 24. Steaming past the forts guarding the mouth of the bay, Farragut engaged and forced the surrender of the Confederate fleet defending the city, capturing Admiral Franklin Buchanan. The city itself, long a desired target of Grant's, would remain in Confederate hands until 1865, but the last seaport east of the Mississippi on the Gulf Coast was closed, further tightening the Union blockade. The capture of Atlanta and Mobile Bay together boosted Northern morale and made an enormous contribution to the re-election of Abraham Lincoln.