William A. Crafts, Life of Ulysses S. Grant: His Boyhood, Campaigns, and Services, Military and Civil.

[77] he had then stated that he did not desire the command. Now, as the most successful and distinguished general in the army, he was naturally selected for-this new and extensive command.

On his way up the Mississippi he received a despatch ordering him, as soon as he was able to take the field, to go to Cairo with his staff. Though yet very weak, he arrived at Cairo on the 16th of October, and immediately reported that he was ready for duty. He was at once ordered to Louisville, where he met the Secretary of War, Mr. Stanton, who brought from Washington the orders creating the new department and appointing Grant to the command. The secretary also bore other orders, which gave the general full power over all the troops in his department, with authority to conduct the campaign according to his own plans. The whole proceeding showed how much confidence the government reposed in Grant, and how much they expected of his military capacity.

There were already rumors, unfounded, however, that Rosecrans was preparing to evacuate Chattanooga, a position of the utmost importance to hold; and it was feared, from the posture of affairs, that, if not abandoned, it would be captured, and thus a still greater disaster would follow the repulse at Chickamauga. Grant, therefore, at the desire of the government, at once assumed the command and sent forward orders, by telegraph, to prevent the deprecated movement, and to relieve Rosecrans.

There was need of prompt action. Rosecrans's army was closely besieged, and Bragg felt confident that he could soon starve him out and, compel a surrender.