Sherman made Atlanta his field headquarters for September and October, changing it entirely from a Southern city to a Northern camp. The whole population was removed, every one being given the choice of going north or south. In his own words, Sherman "had seen Memphis, Vicksburg, Natchez, and New Orleans, all captured from the enemy, and each at once garrisoned by a full division, if not more; so that success was actually crippling our armies in the field by detachments to guard and protect the interests of a hostile population." In reporting to Washington he said: "If the people raise a howl against my barbarity and cruelty, I will answer that war is war, and not popularity seeking. If they want peace, they and their relatives must stop the war." He also excluded the swarms of demoralizing camp-followers that had clogged him elsewhere. One licensed sutler was allowed for each of his three armies, and no more. Atlanta thus became a perfect Union stronghold fixed in the flank of the South.
The balance of losses in action, from May to September, was heavily against the South: nearly nine to four. The actual numbers did not greatly differ: thirty-two thousand Federals to thirty-five thousand Confederates. (And in killed and wounded the Federals lost many more than the Confederates. It was the thirteen thousand captured Confederates that redressed the balance.) But, since Sherman had twice as many in his total as the Confederates had in theirs, the odds in relative loss were nine to four in his favor. The balance of loss from disease was also heavily against the Confedates, who as usual suffered from dearth of medical stores. The losses in present and prospective food supplies were even more in Sherman's favor; for his devastations had begun. Yet Jefferson Davis was bound that Hood should "fight"; and Hood was nothing loth.
Davis went about denouncing Johnston for his magnificent Fabian defense; and added insult to injury by coupling the name of this very able soldier and quite incorruptible man with that of Joseph E. Brown, Governor of Georgia, who, though a violent Secessionist, opposed all proper unification of effort, and exempted eight thousand State employees from conscription as civilian "indispensables." Then, when Sherman approached, Brown ran away with all the food and furniture he could stuff into his own special train; though he left behind him all arms, ammunition, and other warlike stores, besides the confidential documents belonging to the State.
Brown had also weakened Hood's army by withdrawing the State troops to gather in the harvest and store it where Sherman afterwards used what he wanted and destroyed the rest. Yet Hood kept operating in Sherman's rear, admirably seconded by Forrest's and Wheeler's raiding cavalry. Late in October Forrest performed the remarkable feat of taking a flotilla with cavalry. He suddenly swooped down on the Tennessee near Johnsonville and took the gunboat Undine with a couple of transports. Hood had meanwhile been busy on Sherman's line of communications, hoping at least to immobilize him round Atlanta, and at best to bring him back from Georgia for a Federal defeat in Tennessee.
On the fifth of October the last action near Atlanta was fought thirty miles northwest, when Hood made a desperate attempt on Allatoona with a greatly superior force. Twelve miles off, on Kenesaw Mountain, Sherman could see the smoke and hear the sounds of battle through the clear, still, autumn air. But as his signalers could get no answer from the fort he began to fear that Allatoona was already lost, when the signal officer's quick eye caught the faintest flutter at one of the fort windows. Presently the letters, C - R - S - E - H - E - R, were made out; which meant that General John M. Corse, one of the best volunteers produced by the war, was holding out. He had hurried over from Rome, on a call from Allatoona, and was withstanding more than four thousand men with less than two thousand. All morning long the Confederates persisted in their attacks, while Sherman's relief column was hurrying over from Kenesaw. Early in the afternoon the fire slackened and ceased before this column arrived. But Sherman's renewed fears were soon allayed. For Corse, after losing more than a third of his men, had repulsed the enemy alone, inflicting on them an even greater loss in proportion to their double strength.
Corse was still full of fight, reporting back to Kenesaw that though "short a cheek bone and an ear" he was "able to whip all hell yet." Sherman thanked the brave defenders in his general orders of the seventh for "the handsome defense made at Allatoona" and pointed the moral that "garrisons must hold their posts to the last minute, sure that the time gained is valuable and necessary to their comrades at the front."The situation at the beginning of November was most peculiar.
With the whole Gulf coast blockaded and the three great ports in Union hands, with the Mississippi a Union stream from source to sea, and with Sherman firmly set in the northwest flank of Georgia, Hood made the last grand sortie from the beleaguered South. It was a desperate adventure to go north against the Federal troops in Tennessee, with Kentucky and the line of the Ohio as his ultimate objective, when Lincoln had been returned to power, when Grant was surely wearing down Lee in Virginia, and when Sherman's preponderance of force was not only assured in Georgia but in Tennessee as well. Moreover, Thomas, the "Rock of Chickamauga," had been sent back to counter Hood from Grant's and Sherman's old headquarters at Nashville on the Cumberland. And Thomas was soon to have the usual double numbers; for all the Western depots sent him their trained recruits, till, by the end of November, his total was over seventy thousand. Hood's forty thousand could not be increased or even stopped from dwindling.