HEADQUARTERS DEPARTMENT OF THE MISSOURI, OFFICE PROVOST-MARSHAL-GENERAL, Saint Louis, Mo., June 6, 1864.

Colonel WILLIAM HOFFMAN,
Commissary-General of Prisoners, Washington:

COLONEL: I have the honor to acknowledge the receipt of a copy of a letter addressed by you to Colonel Marsh, my predecessor, on the 29th of February last. The report of Surgeon Clark, acting medical inspector of prisoners, of his inspection of the Gratiot Street and Myrtle Street Prisons came to my notice immediately after I assumed the duties of this office and my attention was immediately given to a correction of the evils therein pointed out. Both prisons, especially that of Gratiot Street, were undoubtedly then in a very unsatisfactory condition. They are not so now. Improvements have been made in every respect, and I think I can safely assure you that both are at present in the best possible condition. The duties of my office are such as not to admit of much of my time being given to a direct personal supervision of the details of the interior management of the prisons. As soon as I could obtain the detail of a proper officer for the purpose I appointed an inspector of these prisons and made it his duty to pass through each of them daily, make a minute inspection, and report the result in detail to me. With the advantage of these daily morning reports and a brief interview with him, together with such personal inspections as I can myself from time to time make, I am enabled now to keep the prisons in what I regard, and what I believe is so considered by all who have had an inspection of them, in an entirely satisfactory condition. The walls referred to in your letter as in a falling condition are no longer so. It required but a trifling expense to brace them and put the buildings in a perfectly safe condition. I will give instructions to the acting inspector to make a weekly report every Sunday morning of the condition of the prisoners and prisons, as suggested in your letter, and forward the same to your office with such comments as I may have to make thereon.

Very respectfully, your obedient servant,

J. P. SANDERSON,

Colonel and Provost-Marshal-General.

HEADQUARTERS POST, Chicago, Ill, June 6, 1864.

Colonel W. HOFFMAN,

Commissary-General of Prisoners, Washington, D. C.:

COLONEL: I have the honor to respectfully report that since my letter of June 4, 1864, I have made a careful inspection of the barracks in the garrison square at Camp Douglas with a view to ascertain how many of them would soon be vacated and can be spared from that square with the present garrison. I find about thirty old barracks with kitchens, each barracks with a capacity for 100 men. They can be raised and moved into the prisoners' square without incurring large expense. We have apparatus for moving and raising on hand, and if you desire to fill up the prisoners' square will, of course, lessen the expense in proportion to the number of men they will hold. I invite attention to my letter of June 2, 1864, on the subject of filling the prisoners' square with barracks, in connection with which this letter should be read for full understanding of its suggestions. I respectfully ask instructions at a date as early as practicable. The cost of raising