This from 'The Ulysses S. Grant Association' website (From Southern Illinois University, John Y. Simon, etc.)
http://twister.lib.siu.edu/projects/...28jan1899.html
from chapter 46 of John W. Emerson's series "Grant's Life in the West and His Mississippi Valley Campaigns"
Halleck's Crowning Eccentricity and Want of Judgment.
Before Halleck departed, he was guilty of an act so wanting in wisdom as to be incredible, if it were not too well authenticated for doubt. It was "the talk" in army circles at the time, but the writer doubted the story until Badeau asserted it in his "Military History." He says that it was not meant by Halleck to enlarge Grant's command by the former going to Washington as Commander-in-chief. "On the contrary," he adds, "the new General-in-chief first offered the command of the Army of the Tennessee to Colonel Robert Allen, a quartermaster, who declined it, whereupon it was allowed to remain under Grant."
Colonel Allen being appealed to for the truth of the story, says, in a letter over his own signature: "I had joined General Halleck a short time subsequent to the fall of Corinth, and was attached to his immediate command, when he received his appointment of General-in-chief, with orders to repair at once to Washington. Shortly after he came to my tent.... After a somewhat protracted conversation he turned to me and said: 'Now, what can I do for
you?' I replied that I did not know that he could do anything. 'Yes,' he rejoined, 'I can give you command of this army.' I replied: 'I have not rank.' 'That,' said he, can easily be obtained.' I do not remember exactly what my reply was to this, but it was to the effect that I doubted the expediency of such a measure, identified as I was with the enormous business and expenditures of the quartermaster's department, from which it was almost impracticable to relieve me at that time.... It is true that I was congratulated on the prospect of succeeding to the command, before I had mentioned the subject of this interview."
With Grant, Sherman, Thomas, and other generals who had been campaigning from the beginning with brilliant success, near and ready to act, Halleck was willing to trust the great task to the untried and inexperienced hands of a subordinate quartermaster! With all his unaccountable whimsicalities, the sober thinker would fain believe, or wish to believe, that Halleck was not so insane as this evidence seems to prove; and yet the fact seems proven.
And thus the imperious, eccentric Halleck took his departure from the West, and Grant breathed with more freedom.