r it at a
gallop, believing that all was lost.

But all was not lost. General Thomas commanded the Union left. Like a
flinty rock he stood while Polk's and Longstreet's troops surged in
heavy masses against his front and flank. About three o'clock heavy
columns were seen pouring through a gorge almost in Thomas's rear. They
were Longstreet's men. It was a critical moment Granger's reserves came
rushing upon the field. Raw recruits though they were, they dashed
against Longstreet like veterans. In twenty minutes, at cost of
frightful slaughter, the gorge and ridge were theirs. Longstreet made
another assault, but was again repulsed. At nightfall Thomas fell back
to Chattanooga, henceforth named, and justly, the "Rock of Chickamauga."
For six hours he had held his own with 25,000 braves against twice that
number. Out of 70,000 troops Bragg lost probably 20,000. Rosecrans's
force was about 55,000, his loss 16,000.

[Illustration: Portrait.]
General George H. Thomas.

Bragg proceeded to shut up the Union army in Chattanooga. Grant, now
commanding the Department of the Mississippi, was ordered to recover
Chattanooga, and his deeds along this front, though less often
mentioned, will glitter upon the page of history with little if any less
lustre than those about Vicksburg. Upon his arrival, late in October, he
found the city practically in a state of siege. Its railroad
communication with Nashville was cut off, and supplies had to be hauled
in wagons sixty miles over a rough mountain road. The men had been for
some time on half rations. Thousands of horses and mules had starved,
and the artillery could not be moved for lack of teams. There was not
ammunition enough for one day's fighting. In five days Grant wrested the
railroad from Bragg's men and bridged the Tennessee, so that an abundant
supply of food and ammunition came pouring in.

Elated at his Chickamauga triumph, and unaware that he now had a greater
than Rosecrans in his front, Bragg deemed it a safe and promising
stratagem to despatch Longstreet's corps to Knoxville to capture
Burnside. It was a fatal step, and Grant was not slow to take advantage
of it. He telegraphed Sherman to put his entire force instantly en route
from Vicksburg to Chattanooga.

Chattanooga lies on the south side of the Tennessee River, at the
northern end of a valley running north and south. Along the eastern edge
of the valley rises Missionary Ridge. On the western side and farther