The gorge of the Tennessee where it breaks through these mountain ranges is so narrow and so thoroughly commanded from the heights on both sides as to render it impracticable to so move an army as to attack it from the front or river side.
With these giant obstacles to the progress of his columns, most serious even if they had been within the Union lines, but almost insuperable when found in an enemy's territory, and while he was bending every energy to complete preparations for carrying out a brilliant plan of his own for overcoming them, General Rosecrans was astonished at receiving on August 4, only ten days after his railroad had been repaired to the Tennessee River, a dispatch from Halleck saying: "Your forces must move forward without delay. You will daily report the movement of each corps till you cross the Tennessee River."
To a commander who was building boats, opening mountain roads, rushing the accumulation of stores, getting out material for four thousand feet of bridges, preparing to leave his base carrying provisions for twenty-five days, and ammunition for two battles, and crossing three mountain ranges and a deep and broad river, in an enemy's country, and in the face of an army, this dispatch was not only astounding, but discouraging and exasperating to the last degree.
It had become a habit at Washington to sneer at the slowness of General Rosecrans, as it was later to denounce General Thomas in similar terms at Nashville. There was no more reason or justice in the one case than in the other. The verdict of history has been reached in the case of General Thomas. It is sure to come, and to be the same in this matter, for Rosecrans.
To this dispatch, which can only be excused on the ground of wholly inexcusable ignorance of the active preparations in progress and the natural difficulties of an advance, General Rosecrans replied with his accustomed clearness and spirit: "Your dispatch ordering me to move forward without delay, reporting the movements of each corps till I cross the Tennessee, is received. As I have determined to cross the river as soon as practicable, and have been making all preparations and getting such information as may enable me to do so without being driven back, like Hooker, I wish to know if your order is intended to take away my discretion as to the time and manner of moving my troops." To this Halleck responded: "The orders for the advance of your army, and that it be reported daily, are peremptory." General Rosecrans immediately wrote the following reply, and, calling his corps commanders together, read the dispatches given above. There was no dissent from the proposition that at that stage of their preparations it was impossible to move. He then read his reply as follows, and all approved and agreed that they should support him:
"General Halleck: My arrangements for beginning a continuous movement will be completed and the execution begun Monday next. We have information to show that crossing the Tennessee between Bridgeport and Chattanooga is impracticable, but not enough to show whether we had better cross above Chattanooga and strike Cleveland, or below Bridgeport and strike in their rear. The preliminary movement of troops for the two cases are very different. It is necessary to have our means of crossing the river completed, and our supplies provided to cross sixty miles of mountains and sustain ourselves during the operations of crossing and fighting, before we move. To obey your order literally would be to push our troops into the mountains on narrow and difficult roads, destitute of pasture and forage, and short of water, where they would not be able to maneuver as exigencies may demand, and would certainly cause ultimate delay and probable disaster. If, therefore, the movement which I propose cannot be regarded as obedience to your order, I respectfully request a modification of it or to be relieved from the command."
On the following day Halleck replied as follows:
"I have communicated to you the wishes of the Government in plain and unequivocal terms. The objective has been stated, and you have been directed to lose no time in reaching it. The means you are to employ and the roads you are to follow are left to your own discretion. If you wish to promptly carry out the wishes of the Government you will not stop to discuss mere details. In such matters I do not interfere."
This was answered the same day by General Rosecrans as follows:
"Your dispatch received. I can only repeat the assurance given before the issuance of the order. This army shall move with all dispatch compatible with the successful execution of our work. We are pressing everything to bring up forage for our animals. The present rolling-stock of the road will barely suffice to keep us day by day here, but I have bought fifty more freight cars, which are arriving. Will advise you daily."