About 6 p. m. on the 16th, while on the retreat, the following communication was handed to me:

CAMP, SEVEN MILES FROM JACKSON, May 14, 1863.

GENERAL: The body of troops mentioned in my note of last night compelled Brigadier-General Gregg and his command to evacuate Jackson about noon to-day. The necessity of taking the Canton road at right angles to that upon which the enemy approaches, prevented an obstinate defense. A body of troops, reported this morning to have reached Raymond last night, advanced at the same time from that direction. Prisoners say that it was McPherson's corps (four DIVISIONS), which marched from Clinton. I have no certain information of the other; both skirmished very cautiously.

Telegrams were dispatched when the enemy was near, directing General Gist to assemble the approaching troops at a point 40 or 50 miles from Jackson, and General Maxey to return to his wagons and provide for the security of his brigade; for instance, by joining General Gist. That body of troops will be able, I hope, to prevent the enemy in Jackson from drawing provisions from the east, and this one may be able to keep him from the country toward Panola. Can he supply himself from the Mississippi? Can you not cut him off from it; and, above all, should he be compelled to fall back for want of supplies, beat him? As soon as the re-enforcements are all up, they must be united to the rest of the army. I am anxious to see a force assembled that may be able to inflict a heavy blow upon the enemy. Would it not be better to place the forces to support Vicksburg between General Loring and that place, and merely observe the ferries, so that you might unite if opportunity to fight presented itself? General Gregg will move toward Canton tomorrow. If prisoners tell the truth, the force at Jackson must be half of Grant's army. It would decide the campaign to beat it, which can only be done by concentrating, especially when the remainder of the eastern troops arrive; they are to be 12,000 or 13,000.

Most respectfully, your obedient servant,

J. E. Johnston.

It will be observed that General Johnston's letter of the 15th, which caused me to reverse my column, with a view of marching to Clinton, was received before the retreat commenced, and about eleven hours earlier than the one of the 14th, just presented. I know nothing of the causes which produced this result, but I respectfully invite attention to the fact that in this letter of the 14th General Johnston suggests the very movement which I had made, and for the purpose I had indicated. After expressing the hope that certain dispositions made by himself might prevent the enemy from drawing provisions from the east or from the country toward Panola, he says:

Can he supply himself from the Mississippi? Can you not cut him off from it; and, above all, should he be compelled to fall back for want of supplies, beat him?

I have introduced General Johnston's letter entire, that the context, as well as that portion to which I have particularly called attention, may be considered. I had resisted the popular clamor for an advance, which began from the moment the enemy set his polluting foot upon the eastern bank of the Mississippi River. I had resisted the universal sentiment, I believe of the army-I know of my general officers-in its favor, and yielded only to the orders of my superior. I was not invited by General Johnston to submit my plans to him for his consideration; it is, therefore, unnecessary now to speak of them.

One of the immediate results of the retreat from Big Black was the necessity of abandoning our defenses on the Yahoo at Snyder's Mill.

That position and the line of Chickasaw Bayou were no longer tenable. All stores that could be transported were ordered to be sent into Vicksburg as rapidly as possible; the rest, including heavy guns, to be destroyed.

There was at this time a large quantity of corn (probably 25,000 or 30,000 bushels) on boats, much of which might have been brought in had it been possible to furnish the necessary wagons. The boats were