The day after sending to Mr. Stanton this letter on the generals of divisions and of brigades in the army which besieged Vicksburg, I wrote him another on the staff officers of the various corps. Like its predecessor, this letter has never appeared in the records of the war:

Cairo, Ill., July 13, 1863.

Dear Sir: In my letter of yesterday I accidentally omitted to notice General C. C. Washburn among the generals of division in Grant's army. He is now in command of two of the divisions detached from the Sixteenth Army Corps—namely, that of Kimball and that of W. S. Smith—and, as I happen to know, is anxious to be put in command of an army corps, for which purpose it has been suggested that a new corps might be created out of these two divisions, with the addition of that of Lauman, also detached from the Sixteenth, or that of Herron. But I understand from General Grant that he is not favorable to any such arrangement. Washburn being one of the very youngest in rank of his major generals, he intends to put him in command of a single division as soon as possible, in order that he may prove his fitness for higher commands by actual service, and give no occasion for older soldiers to complain that he is promoted without regard to his merits.

I know Washburn very well, both as a politician and a military man, and I say frankly that he has better qualities for the latter than for the former function. He is brave, steady, respectable; receives suggestions and weighs them carefully; is not above being advised, but acts with independence nevertheless. His judgment is good, and his vigilance sufficient. I have not seen him in battle, however, and can not say how far he holds his mind there. I don't find in him, I am sorry to say, that effort to learn the military art which every commander ought to exhibit, no matter whether he has received a military education or not. Washburn's whole soul is not put into the business of arms, and for me that is an unpardonable defect. But he is a good man, and above the average of our generals, at least of those in Grant's command.

I now come to the staff organization and staff officers of this army, beginning, of course, with those connected with the head of the department. Grant's staff is a curious mixture of good, bad, and indifferent. As he is neither an organizer nor a disciplinarian himself, his staff is naturally a mosaic of accidental elements and family friends. It contains four working men, two who are able to accomplish their duties without much work, and several who either don't think of work, or who accomplish nothing no matter what they undertake.

Lieutenant-Colonel Rawlins, Grant's assistant adjutant general, is a very industrious, conscientious man, who never loses a moment, and never gives himself any indulgence except swearing and scolding. He is a lawyer by profession, a townsman of Grant's, and has a great influence over him, especially because he watches him day and night, and whenever he commits the folly of tasting liquor hastens to remind him that at the beginning of the war he gave him [Rawlins] his word of honor not to touch a drop as long as it lasted. Grant thinks Rawlins a first-rate adjutant, but I think this is a mistake. He is too slow, and can't write the English language correctly without a great deal of careful consideration. Indeed, illiterateness is a general characteristic of Grant's staff, and in fact of Grant's generals and regimental officers of all ranks.

Major Bowers, judge-advocate of Grant's staff, is an excellent man, and always finds work to do. Lieutenant-Colonel Wilson, inspector general, is a person of similar disposition. He is a captain of engineers in the regular army, and has rendered valuable services in that capacity. The fortifications of Haynes's Bluff were designed by him and executed under his direction. His leading idea is the idea of duty, and he applies it vigorously and often impatiently to others. In consequence he is unpopular among all who like to live with little work. But he has remarkable talents and uncommon executive power, and will be heard from hereafter.

The quartermaster's department is under charge of Lieutenant-Colonel Bingham, who is one of those I spoke of as accomplishing much with little work. He is an invalid almost, and I have never seen him when he appeared to be perfectly well; but he is a man of first-rate abilities and solid character, and, barring physical weakness, up to even greater responsibilities than those he now bears.

The chief commissary, Lieutenant-Colonel Macfeely, is a jolly, agreeable fellow, who never seems to be at work, but I have heard no complaints of deficiencies in his department. On the contrary, it seems to be one of the most efficacious parts of this great machine.

Lieutenant-Colonel Kent, provost-marshal general, is a very industrious and sensible man, a great improvement on his predecessor, Colonel Hillyer, who was a family and personal friend of Grant's.