Who in the Union Army High Command?
Grant primarily though Stanton and Scott must have had input as well. There was Congressional investigation/testimony about this in later years.
In refutation of the charge that prisoners were starved, let it be noted that the Confederate Congress in May, 1861, passed a bill providing that the rations furnished to prisoners of war should be the same in quantity and quality as those issued to the enlisted men in the army of the Confederacy. And the prisoners at Andersonville received the same rations that were furnished the Confederate guard.
During the amnesty debate in the House of Representatives in 1876, Hill, of Georgia, replying to statements of Blaine, discussed the history of the exchange of prisoners, dwelling on the fact that the cartel which was established in 1862 was interrupted in 1863, and that the Federal authorities refused to continue the exchange of prisoners. “The next effort,” he said, “in the same direction was made in January, 1864, when Robert Ould, Confederate agent of exchange, wrote to the Federal agent of exchange, proposing, in view of the difficulties attending the release of prisoners, that the surgeons of the army on each side be allowed to attend their own soldiers while prisoners in the hands of the enemy, and should have charge of their nursing and medicine and provisions; which proposition was also rejected.”
Continuing, Mr. Hill said: “In August, 1864, there were two more propositions. The cartel of exchange had been broken by the Federals under certain pretences, and the prisoners were accumulating on both sides to such an extent that Mr. Ould made another proposition to waive every objection and to agree to whatever terms the Federal Government would demand, and to renew the exchange of prisoners, man for man, and officer for officer, just as the Federal Government might prescribe. That proposition was also rejected. In the same month, August, 1864, finding that the Federal Government would neither exchange prisoners nor agree to sending surgeons to the prisoners on each side, the Confederate Government officially proposed, in August, 1864, that if the Federal Government would send steamers and transports to Savannah, the Confederate Government would return the sick and wounded prisoners on its hands without an equivalent. That proposition, which was communicated to the Federal authorities in August, 1864, was not answered until December, 1864, when some ships were sent to Savannah. The record will show that the chief suffering, the chief mortality at Andersonville, was between August and December, 1864. We sought to allay that suffering by asking you to take your prisoners off our hands without equivalent, and without asking you to return a man for them, and you refused.”
Mr. Hill quoted a series of resolutions passed by the Federal prisoners at Andersonville in 1864, September 28th, in which all due praise is given the Confederate Government for the attention paid them, and in which it was said that the sufferings which they endured were not caused intentionally by the Confederate Government, but by the force of circumstances. Commenting, Mr. Hill said: “Brave men are always honest, and true soldiers never slander; I would believe the statement of those gallant soldiers at Andersonville, as contained in those resolutions, in preference to the whole tribe of Republican politicians.”
Cite correspondence by Grant to the “high Command” Grant was up to his ass at Vicksburg at the time the prisoner of war negotiations were going on.