Johnston's Movements--Fortifications At Haines' Bluff-- Explosion Of The Mine--Explosion Of The Second Mine--Preparing For The Assault--The Flag Of Truce--Meeting With Pemberton-- Negotiations For Surrender--Accepting The Terms-- Surrender Of Vicksburg.
On the 22d of June positive information was received that Johnston had crossed the Big Black River for the purpose of attacking our rear, to raise the siege and release Pemberton. The correspondence between Johnston and Pemberton shows that all expectation of holding Vicksburg had by this time passed from Johnston's mind. I immediately ordered Sherman to the command of all the forces from Haines' Bluff to the Big Black River. This amounted now to quite half the troops about Vicksburg. Besides these, Herron and A. J. Smith's divisions were ordered to hold themselves in readiness to reinforce Sherman. Haines' Bluff had been strongly fortified on the land side, and on all commanding points from there to the Big Black at the railroad crossing batteries had been constructed. The work of connecting by rifle-pits where this was not already done, was an easy task for the troops that were to defend them.

We were now looking west, besieging Pemberton, while we were also looking east to defend ourselves against an expected siege by Johnston. But as against the garrison of Vicksburg we were as substantially protected as they were against us. Where we were looking east and north we were strongly fortified, and on the defensive. Johnston evidently took in the situation and wisely, I think, abstained from making an assault on us because it would simply have inflicted loss on both sides without accomplishing any result. We were strong enough to have taken the offensive against him; but I did not feel disposed to take any risk of losing our hold upon Pemberton's army, while I would have rejoiced at the opportunity of defending ourselves against an attack by Johnston.