ground lost, since the fall of Fort Henry, by
pushing northward in this direction. Halleck's dispersion of forces had
sent Buell to this section, and Buell had been superseded by Rosecrans,
a zealous and patriotic but unfortunate commander. The repulse at
Chickamauga might have proved disastrous to his army but for the
splendid behavior of the division under General Thomas, an officer not
unlike Grant in the mould of his military talent, who there earned the
sobriquet, "The Rock of Chickamauga."

The army of Rosecrans had been gathered again at Chattanooga, where it
was confronted by Bragg, whose force surrounded it in an irregular
semicircle from the Tennessee River to the river again, occupying
Missionary Ridge on one flank and Lookout Mountain on the other, with
its centre where these two ridges come nearly together. Chattanooga was
in the valley between, near the centre of which, behind the town, was an
elevation, Orchard Knob, held by the enemy. Bragg commanded the river
and the railroads. The route for supplies was circuitous, inadequate,
and insecure, over mountain roads that had become horrible. Horses and
mules had perished by thousands. The soldiers were on half rations. Word
came to Grant in Louisville, that Rosecrans was contemplating a retreat.
He at once issued an order assuming his new command, notified Rosecrans
that he was relieved, and instructed Thomas to hold the place at all
hazards until he reached the front.

Still so lame that he could not walk without crutches, and had to be
carried in arms over places where it was not safe to go on horseback, he
left Louisville on the 21st of October, and reached Chattanooga on the
evening of the 23d. Then began a work of masterly activity and
preparation, in which his genius again asserted its supreme quality.
Sherman with his army was ordered to join Grant. In five days the river
road to Bridgeport was opened, the enemy being driven from the banks,
two bridges were built, and Hooker's army added to his force. The enemy,
having a much superior force, and assuming the surrender of the Army of
the Cumberland to be only a question of time and famine, sent Longstreet
with 15,000 men to reinforce the army of Johnston, holding Burnside in
Knoxville, to the relief of whom the enemy supposed Sherman to be
marching. Grant waited for Sherman, who was coming on between Longstreet
and Bragg. All general orders for the battle were prepared in advance,
except their dates.