Those individuals on both sides of the argument for and against McClellan and his conduct in the Maryland Campaign should consider reading Steven Stotelmyer's book, 'Too Useful To Sacrifice' (shown below).
Both sides seem to be fairly entrenched in their views on McClellan with the problem being that even many of the so called 'facts' can be embellished with different interpretations depending on the outlook of the author.
Having considered this campaign for many years I would just like to make a few personal observations:
1. Several well known authors have seemingly started out with a definite narrative and then picked the facts or interpretations of them to suit that narrative. This may be an accepted method of historical reporting in order to sell more books but has the problem of not being as unbiased as any truly reflective historical report or book perhaps should be.
2. These 'views' once published have a habit of being repeated throughout the ages - a 'once written in stone' mentality and is a consequence of either poor research, poor referencing or time constraints on publishing schedules.
3. The outlook that historians have is generally influenced by access to subsequent information that was unavailable to those at the time (beautifully illustrated and discussed in depth by Joseph Harsh in his excellent 'Taken at the Flood') and is further compounded by the impact of what is the present day view is on these events.
4. Reporting of McClellan's generalship is heavily influenced by both his personality traits, his political stance and the overt and sometimes shocking criticism of figures that have become to some extent immortalised - Lincoln being the prime example.
5. Often the criticism is so great that in order to counter this tsunami of 'bad press' the counter argument is also embellished so that the only thing left are the two extremes and little if any of the centre ground remains. People are deemed to be 'for' or 'against' and there is no alternative apart from these two extremes. One might argue that Stotelmyer is sometimes guilty of overpresenting his case as a consequence of trying to 'swim against the tide'.
My final point is to try and look past the 'facts' and look at the overall picture such as with the statement - 'what was achieved?'
From my point of view I could never understand how Meade could be virtually sanctified for saving the Union at Gettysburg. Yet despite this would be castigated for his subsequent 'failure' to destroy the AoNV in the pursuit afterwards and even more criticism for the Bristoe and Wilderness Campaign.
In contrast McClellan had by far the most difficult job. He had inherited a demoralised and badly beaten army that had shortfalls in both ammunition and provisions, had seen the North invaded for the first time in its history and as a consequence of these events was at serious risk of losing the war. It was extremely unlikely that McClellan could have won the war either on the Peninsula or after the Antietam campaign, as in hindsight it even took Grant (combined with a fair amount of luck!) 18 months to grind down the AoNV to a point where it could no longer continue the war. A further requirement was a highly co-ordinated strategy that threatened the Confederacy at its most vulnerable points. So a 'quick fix' often proposed by many arguing against McClellan was in effect unattainable simply due to the highly effective mobilisation of assets within the Confederacy.
So McClellan's major aims on taking over from Pope were to reinvigorate and resupply the army so that it was able to resist the AoNV for any immediate battle. To prevent the further invasion of any more northern states and repel the AoNV back into Virginia. To attain a victory that would enable Lincoln to issue his Emancipation Proclamation (although he did not know it at the time) and thereby change the course of the war by preventing foreign intervention.
To all intents and purposes all of these objectives were achieved and with considerable success.
If Meade can therefore be proclaimed as 'Saviour of the Union' in 1863, surely what is the problem of applying the same tag to McClellan for 1862 despite what you may think of his personal characterics, political beliefs or personality flaws?
Read 'Too Useful To Sacrifice' - it may change your mind!