The threatening manoeuvres of Sherman alone caused the rebel authorities to diminish the number of inmates of this stockade, and thereby lessen the dangers of recapture, and remove the temptation to the United States authorities to make an effort for their rescue. It has been stated that the rebels were anxious to exchange prisoners, man for man, and that the obstructions were caused by the Federal authorities, and that Mr. Stanton, in particular, was responsible for the stoppage of exchange and the consequent death of so many thousands of our fellow-citizens detained in the rebel prisons. General Hitchcock, the United States commissioner of exchange, however, denies most emphatically that Mr. Stanton was any way responsible for the refusal to make exchanges, man for man, officer for officer, according to grade, and he makes the following statement: "At no instance within my knowledge did Mr. Stanton refuse to acquiesce in any proposition looking to that result. There is not in my office, nor have I ever seen such a proposition from a rebel commissioner or the rebel authorities. Nor have I any reason to believe that any such proposition was ever made by Judge Ould, or any of his superiors, except in a letter from Judge Ould addressed to Major Mulford, which fell into the hands of Major-General Butler. This is true, emphatically, as a protection against the accusations levelled at Mr. Stanton. * * * * * Mr. Stanton has not only been willing, but anxious to make exchanges referred to, as I have abundant means of showing by indisputable documents, the aim and purpose of Judge Ould was to draw from us all of the rebel prisoners held in exchange for white troops of the United States held as prisoners in the South, persistently refusing to exchange colored troops to a very late date; when, to carry a special purpose, he receded so far as to agree to exchange free colored men, leaving the general principle where it was on his side against the just claims of a large body of colored prisoners held in the South." XVII. The following letter from General Butler to the rebel commissioner of exchange will throw some light upon the subject, and give an idea as to whom the blame of non-exchange and non-intercourse belongs:-- _Letter of Major-General Butler, United States Commissioner of Exchange, to Colonel Ould, the Confederate Commissioner._ HEADQUARTERS DEPARTMENT OF VIRGINIA AND NORTH} CAROLINA, IN THE FIELD, AUGUST, 1864. } HON. ROBERT OULD, _Commissioner of Exchange_. SIR: Your note to Major Mulford, assistant agent of exchange, under date of 10th August, has been referred to me.