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.