Atlanta Campaign

The Atlanta Campaign (6 May 1864 – 2 September 1864) was a series of battles during the American Civil War. The campaign was planned and executed by the Union Army under Major general William T. Sherman. The first part of the plan was to defeat the Confederate Army of Tennessee led by General Joseph E. Johnston. The second goal was to take the important city of Atlanta. Sherman captured Atlanta but was unable to completely destroy the Army of Tennessee.
Background.
The war had been going on for three years when Ulysses S. Grant was given command of the Union Army. While a much smaller army, the Confederates had been moving their forces to battle whichever Union army was active at the time. By doing this they had won most of the battles. Grant decided to coordinate his armies and defeat the confederates. His field armies would all engage the confederate field armies at the same time. This would pin down the smaller southern armies so the Union army could defeat them. Grant would personally lead the Army of the Potomac against Confederate general General Robert E. Lee and his Army of Northern Virginia. He would try to capture the capital of the confederacy, Richmond. Sherman would move his army against Johnston and capture the South's second largest city, Atlanta. If successful, it would shorten the war and get President Abraham Lincoln reelected that November. If they failed, Lincoln would lose the election and the southern states might break away permanently.
The campaign.
By 1864, the Confederacy knew they could not defeat the stronger Union army. But they could win the war by simply not losing to the North. They would keep fighting until the Union got tired of war and asked for peace. Lee had to defend Richmond and keep the Union army away. Johnson had to defend Atlanta and keep their supply lines open.
Sherman had over 100,000 men he divided into three field armies. Johnson had 53,800 men. At the last minute he received another 15,000 men making his the larger of the two main Southern armies. But it was still only about half the size of the Union army facing him. In the opening weeks of the campaign Sherman forced Johnston's confederates back from one place to another. Repeatedly Sherman moved two of his field armies against Johnston while a third army under James B. McPherson threatened the supply lines. McPherson's army was also used in flanking maneuvers. Sherman's combined armies kept moving towards Atlanta while Johnson's armies fell back. Finally Johnson retreated into Atlanta on July 9–10. Jefferson Davis the Confederate president, dismissed Johnson for not stopping the Union army. He gave command to John B. Hood, Johnson's second in command. Hood had little chance of succeeding. Sherman's army was five miles from the city when Hood took command.
Siege of Atlanta.
Hood ordered his men to attack Sherman's army on July 20. The attempts failed and by July 22 Hood had lost 8,000 men to Sherman's losses of about 3,000. Hood retreated back into Atlanta again. Sherman set up his cannon and began a bombardment of Atlanta that would last a month. Then Sherman withdrew his armies leaving only a small force. Hood's army followed them to Jonesboro, Georgia. Sherman's army cut Hoods line of retreat back to Atlanta. The Battle of Jonesborough lasted two days and ended on 1 September. After taking heavy casualties what was left of Hood's army burned their supplies and ammunition and left Atlanta. Sherman then took Atlanta. This was a major loss for the confederacy. It almost guaranteed Lincoln's reelection. It also led to the next campaign, Sherman's March to the Sea.