The Drive on Atlanta
As winter turned to spring in 1864, William T. Sherman was in Chattanooga with 100,000 troops, mainly western veterans of the Vicksburg and Chattanooga campaigns. Grant's plan to end the war was to press the Confederate armies along all fronts at once, the main two thrusts being south toward Richmond, Virginia, and southeast from Chattanooga toward Atlanta, Georgia, along the Western & Atlantic Railroad. If Sherman could take Atlanta, an important rail and industrial hub of the Deep South, the North would deprive the Confederacy of an important transportation and industrial resource and demonstrate to its people and the world that it could not defend its principal cities.
“The W&A RR of Georgia should be the pride of every true American because by reason of its existence the Union was saved. Every foot of it should be sacred ground, because it was once moistened with patriotic blood. Over a hundred miles of it was fought in a continuous battle of 120 days, during which, night and day, were heard the continuous boom of cannon and the sharp crack of the rifle.” — General William T. Sherman on the Atlanta campaign
Grant had exceptional confidence in Sherman; he had worked with the man since the early months of the war and he knew Sherman's capabilities. Moreover, Sherman had the larger army and adequate supplies. He faced an army of only 62,000 men, which the South struggled to keep in the field. Sherman, however, understood that he faced a very difficult task. President Davis had finally given up on Braxton Bragg after the Battle of Chattanooga and put Joseph Johnston in charge of the Army of Tennessee. Johnston was a competent and crafty general, seasoned by the war and not likely to make mistakes. Moreover, the terrain was hilly and cut up, favoring defense. The further Sherman advanced, the longer his supply line back to Chattanooga and the north, forcing him to leave troops for garrison duty along the rail line.
Johnston recognized the folly of attacking Sherman directly, so he tried a different strategy: he planned to keep Sherman away from Atlanta as long as possible, at least until the November elections. He had two reasons: he hoped many of Sherman's soldiers would leave when their enlistments were up before summer, and a war-weary North might replace President Lincoln with someone more willing to negotiate a peace that included Southern independence.
Johnston's plan was to take up defensive positions to forestall Sherman's movements, but Sherman was able to outflank Johnston in position after position until Sherman reached the outskirts of Atlanta. Tired of Johnston's retreats, President Davis relieved him of duty and gave his army to the younger and more aggressive John B. Hood.

