outh side of the
Tennessee, where Missionary Ridge would strike it if prolonged, and a
sufficient number of men to man the boats were to push to the north side
to ferry over the main body of Sherman's command while those left on the
south side intrenched themselves. Thomas was to move out from his lines
facing the ridge, leaving enough of Palmer's corps to guard against an
attack down the valley. Lookout Valley being of no present value to us,
and being untenable by the enemy if we should secure Missionary Ridge,
Hooker's orders were changed. His revised orders brought him to
Chattanooga by the established route north of the Tennessee. He was
then to move out to the right to Rossville.

Hooker's position in Lookout Valley was absolutely essential to us so
long as Chattanooga was besieged. It was the key to our line for
supplying the army. But it was not essential after the enemy was
dispersed from our front, or even after the battle for this purpose was
begun. Hooker's orders, therefore, were designed to get his force past
Lookout Mountain and Chattanooga Valley, and up to Missionary Ridge. By
crossing the north face of Lookout the troops would come into
Chattanooga Valley in rear of the line held by the enemy across the
valley, and would necessarily force its evacuation. Orders were
accordingly given to march by this route. But days before the battle
began the advantages as well as the disadvantages of this plan of action
were all considered. The passage over the mountain was a difficult one
to make in the face of an enemy. It might consume so much time as to
lose us the use of the troops engaged in it at other points where they
were more wanted. After reaching Chattanooga Valley, the creek of the
same name, quite a formidable stream to get an army over, had to be
crossed. I was perfectly willing that the enemy should keep Lookout
Mountain until we got through with the troops on Missionary Ridge. By
marching Hooker to the north side of the river, thence up the stream,
and recrossing at the town, he could be got in position at any named
time; when in this new position, he would have Chattanooga Creek behind
him, and the attack on Missionary Ridge would unquestionably cause the
evacuation by the enemy of his line across the valley and on Lookout
Mountain. Hooker's order was changed accordingly. As explained
elsewhere, the original order had to be reverted to, because of a flood
in the river rendering the