... he agreed to deliver a message from him [John A. McClernand] to General McClellan, whom rumor had on the verge of again being relieved...Next: McClellan acquiesces.
Soon afterward, Wilson returned to Maryland, testified at the court martial, and then encountered Little Mac and secured an audience with him. Seated inside McClellan's headquarters tent, he relayed General McClernand's suggestion that Little Mac seek the united command in the Mississippi Valley.
Wilson understood McClernand's reasoning, and believed that his host did also. As a figure of national prominence, McClellan stood a chance of winning such a promotion [sic] more easily than McClernand could. If the Illinois politician offered him help in attaining that goal, McClellan might be so gratefulas to tender him a command higher than any he could secure on his own.
When Wilson finished speaking, General McClellan candidly admitted the probability of his impending relief. But he dismissed McClernand's suggestion with a wave of his hand. He was so attached to "his" Army of the Potomac, that if denied authority over them he could not even consider accepting another command.
This evidence of McClellan's unwillingness to subordinate personal considerations to the greater concept of the nation's well-being [i.e., McClernand's well-being] dismayed Wilson. Of course, Wilson had himself displayed the same tendency...In any case, he took it upon himself to deliver a fervent little lecture... "Pardon me general, if I add - if they don't give you an army, you should take an army corps or even a division. If they will not give you a division, were I in your place, I should ask for a brigade. If they deny that, I should resign and go back to my state and raise a regiment. If I couldn't get a colonelcy, I should take on any position open to me, and failing a commission, I should take my musket and go out as a private soldier!"
Strange advice for a junior lieutenant to give a major general and army commander. But it was a right-minded suggestion. McClellan apparently took no offense at the outburst. He remarked, however, that no one had ever spoken to him in such a manner. Yet when he said he would think over Wilson's advice, he smiled meaninglessly. Seeing that his words had not produced the desired effect, Wilson sadly left the tent, remounted, and started back to Washington.
In the capital, he gave John McClernand the gloomy news.
McClellan for Vicksburg 2/3
The following is from Edward Longacre's book Grant's Cavalryman: The Life and Wars of General James H. Wilson. Longacre's note-free text was sourced to a brief free-form notes section at the end of the book in which each chapter is roughly correlated to a few items of source material (say, four notes per chapter). If I read this ambiguous and inadequate section correctly, the following information originated in Wilson's diary. Parentheticals are my own: