Here is an assessment of Rosecrans made by the NY Times a few days after his removal from command of the AotC.
I think its importance isn't so much it's historical accuracy but the sense it gives of contemporary opinion about Rosecrans during the war. I have boldfaced a few sentences I think are of particular interest.
The Removal of Gen. Rosecrans.
Published: October 22, 186
As we are not of the number of those who think that the President ought to take the vote of the people and of the army before removing or appointing a General, we have no fault to find with the dismissal of Gen. ROSECRANS from his command in Tennessee. We are bound, at least in courtesy, to suppose that there are good reasons for a step in many respects so grave, and that in this, as in other things, the President has been guided, in the exercise of an undoubted prerogative, by a sense of duty, and by nothing else. What these reasons are it would be idle now to inquire. It would be just neither to Gen. ROSECRANS nor to the Government to discuss seriously the dozen rumors which are flying from lip to lip touching the General's alleged mistakes, or shortcomings, or misfortunes. We may be sure that we shall know in due time whatever he considers it necessary for the vindication of his own fame that we should know, and until that time comes we may well be spared the task of investigating the probability or improbability of every bit of camp gossip that is offered to us in explanation of one of the most untoward incidents of the war.
Whatever be the cause of it, however, and let it be ever so much called for by the exigencies of the actual crisis, there are few people who will learn of ROSECRANS' removal from the field of his last year's labors, without sincere and hearty regret. His being succeeded by such a man as GRANT, is, of course, an ample guarantee that the Republic will not suffer by the change, and that it indicates no lack of earnestness or zeal at headquarters. Nobody can be fitter to give the rebellion its deathblow in Georgia and South Carolina, than the man who wrested from it the valley of the Mississippi. But there are occasions when personal sympathy speaks still more loudly than public spirit, and when even one's interest in the fortunes of the nation, is momentarily obscured by our interest in the fortunes of those who have served it faithfully and well; and Gen. ROSECRANS' retirement is certainly one of these occasions. We feel confident that he will still bear a prominent part in finishing the work in which he has already borne so brilliant a share in beginning; but whether he does or not, no history of the rebellion will ever be written in which his name will not occupy a leading place. We care not whether it was he or MCCLELLAN who was entitled to the credit of those small successes in Western Virginia, in the Summer of 1861, by which so many people fondly hoped at that time "the back of the rebellion had been broken." It is enough for his fame, and enough for our respect and admiration, that he should have commanded at Iuka and Corinth; that, having taken a broken, dispirited and disorganized army out of the palsied hands of BUELL, he should in nine months have converted it into a machine of matchless efficiency and precision -- a host whose spirit and discipline has astonished the most exacting of military critics, and that in that same period he should have driven a victorious enemy out of so vast an area of Tennessee and Kentucky; and not only this, but have fixed a grasp of steel on the very position in the very heart of their territory, which the highest rebel authorities pronounced, two years ago, the key of the eastern States, and which they are at this hour concentrating all their resources to recover. There is many a military hero who considers his repose and laurels well won with half such achievements as these. There is but one military man living who has accomplished more, and that is GRANT.
And perhaps not the least of ROSECRANS' claims on our gratitude and esteem, is the heartiness of that enthusiasm for the cause which he has so well defended. The services we get from many of our trained officers are so strictly professional, that when an educated and successful soldier like ROSECRANS brings his faith with him into the field, and fights as his very highest duty, we must be hardly worth fighting for, if to be served in such fashion as this does not win from us something more than commonplace thanks. He has, there is no denying it, much of that sacred fire, which, if it had been more widely diffused, might, ere this, have produced more satisfactory results than those we witness to-day. We are, consequently, all grateful for the example of his zeal, his devotion and his integrity, and we think we may safely say that the misfortune which has momentarily dimmed the lustre of his fame, has not deprived him of one jot of the popular sympathy and esteem.
)
Bringing the