Stephen E. Ambrose. Halleck: Lincoln's Chief of Staff, Baton Rouge, LSU, 1990
Halleck was ignorant of these movements [McClellan's advance into Maryland]. [...] McClellan felt he could not take the few minutes necessary to inform Halleck of his moves.
Note: In just seven days before Antietam September 10 -16 (inclusive), McClellan sent 17 messages to Halleck. In the two days before making contact with the enemy, McClellan telegraphed Halleck three times per day. McClellan also wrote and cabled Lincoln during this time, expecting Lincoln and Halleck to communicate. Additionally McClellan's staff maintained contact with Halleck's staff and McClellan's cavalry commander, Gen. Pleasanton, frequently updated Washington with word of his own movements.
Douglas S. Freeman. Lee: An Abridgement in One Volume by Richard Harwell, Scribners, New York, 1961
It was soon known that McClellan had replaced Pope in general command and that was not pleasant news, for Lee regarded McClellan as the ablest of the Federal commanders.
Note: At this point, Lee had faced only McClellan and Pope (and T. Sherman and Rosecrans). Lee's "ablest" judgement was made and disclosed much later, after he had also faced Grant, Butler, Meade, Hooker, Sheridan, and Burnside.
Shelby Foote. The Civil War: A Narrative, Vintage, New York, 1986
In fact he [Lincoln] was after the top-ranking man in the whole U.S. Army: George B. McClellan.
Note: After Antietam, McClellan was the highest ranking man on active duty with a field command. He was not the top-ranking man in the whole U.S. Army.
James M. McPherson. Battle Cry of Freedom: the Civil War Era, Oxford, New York. 1988
When McClellan had first arrived in Washington he expressed an intent to "carry this thing 'en grande' & crush the rebels in one campaign." Republicans thought this had the right ring.
Note: Republicans could never have known. It was written in a private letter to his wife.
Carl Sandburg. Storm Over the Land: A Profile of the Civil War. Harcourt, Brace and World, New York, 1942
More serious was the point that McClellan had stripped Washington of all defence troops except some 20,000.
Note: McClellan left about 18,000 men within Washington city, 7,780 at Warrenton, 10,859 at Manassas, and 1,350 on the lower Potomac -- all for the defence of Washington. He also left 35,467 men under Banks in the Valley, also for the defence of Washington.
Stephen W. Sears. George B. McClellan, The Young Napoleon. Ticknor & Fields, New York
Not until more than three hours after first light on September 15  were any orders for an advance sent out from [McClellan's] headqaurters, and subsequent orders were conflicting and hedged about with cautions.
Note: On the night of Sept. 14/15, McClellan issued orders to his corps commanders to press their pickets forward at dawn. Once the enemy was discovered withdrawing, further orders were needed and immediately given to pursue. McClellan wired Halleck at 8:00 am that he had begun the pursuit. The cavalry and elements of the IX Corps had started by 8:00 am. Similar unit morning move-out times are easily traced in unit histories and such books as Roads to Antietam by Schildt and Before Antietam by Priest.
Stephen W. Sears. "Lincoln and McClellan" in Lincoln's Generals, G. Borritt, ed., Oxford, New York, 1994
...Lincoln had to make a second, highly difficult decision - to permit McClellan to take the field in pursuit. He did do on September 3 , during a visit to McClellan's Washington house in company with General Halleck.
Note: Lincoln and Halleck visited McClellan's house on Sept. 2, not Sept. 3. Aside from an assertion by Halleck, there is no evidence Lincoln made this decision and Lincoln himself denied ever making it. (For more on this, see FAC and book review.)
James L. Stokesbury. A Short History of the Civil War, William Morrow and Company, New York, 1995
The government in Washington reacted quickly to restore confidence, and they did so by relieving Pope and reappointing McClellan. The latter put on a full dress uniform and went out to meet the troops as they marched...
Note: Pope was not relieved until several days after after the troops met McClellan on their march into D.C. Neither was McClellan "reappointed" (see FAC).
Edmund Wilson. Patriotic Gore, Oxford, New York, 1962
He [Lee] regretted the dismissal of McClellan and the substitution of Grant because, as he said, he had always understood pretty well how McClellan was going to act but he could not be sure of Grant.
Note: (1) Grant never replaced McClellan. (2) Lee actually said that he feared the enemy would keep changing commanders until they found someone he did not understand. This bravado came with McClellan's replacement by Burnside in 1862.
... a note found after his [Lincoln's] death dates from the autumn of 1862, a time when he was much discouraged by the failures of George McClellan, his general-in-chief.
Note: In the autumn of 1862, Lincoln's general-in-chief was Henry W. Halleck, in whose failures he was indeed much discouraged.
William Wood. Captains of the Civil War: A Chronicle of the Blue and the Gray, Yale Chronicle Series, Yale University Press, New York, 1921Scott, unable to take to the field at 75, had no second-in-command. Halleck was a very poor substitute later on. In the meantime, McDowell was chosen and generously helped by Lincoln and Stanton.
Note: Stanton was not in the Administration when McDowell was chosen. Perhaps McDowell was helped by Lincoln and Cameron.