On the 26th of May I sent Blair’s division up the Yazoo to drive out a force of the enemy supposed to be between the Big Black and the Yazoo. The country was rich and full of supplies of both food and forage. Blair was instructed to take all of it. The cattle were to be driven in for the use of our army, and the food and forage to be consumed by our troops or destroyed by fire; all bridges were to be destroyed, and the roads rendered as nearly impassable as possible. Blair went forty-five miles and was gone almost a week. His work was effectually done. I requested Porter at this time to send the marine brigade, a floating nondescript force which had been assigned to his command and which proved very useful, up to Haines’ Bluff to hold it until reinforcements could be sent.
On the 26th I also received a letter from Banks, asking me to reinforce him with ten thousand men at Port Hudson. Of course I could not comply with his request, nor did I think he needed them. He was in no danger of an attack by the garrison in his front, and there was no army organizing in his rear to raise the siege.
On the 3d of June a brigade from Hurlbut’s command arrived, General Kimball commanding. It was sent to Mechanicsburg, some miles north-east of Haines’ Bluff and about midway between the Big Black and the Yazoo. A brigade of Blair’s division and twelve hundred cavalry had already, on Blair’s return from the Yazoo, been sent to the same place with instructions to watch the crossings of the Big Black River, to destroy the roads in his (Blair’s) front, and to gather or destroy all supplies.
On the 7th of June our little force of colored and white troops across the Mississippi, at Milliken’s Bend, were attacked by about 3,000 men from Richard Taylor’s trans-Mississippi command. With the aid of the gunboats they were speedily repelled. I sent Mower’s brigade over with instructions to drive the enemy beyond the Tensas Bayou; and we had no further trouble in that quarter during the siege. This was the first important engagement of the war in which colored troops were under fire. These men were very raw, having all been enlisted since the beginning of the siege, but they behaved well.
On the 8th of June a full division arrived from Hurlbut’s command, under General Sooy Smith. It was sent immediately to Haines’ Bluff, and General C. C. Washburn was assigned to the general command at that point.
On the 11th a strong division arrived from the Department of the Missouri under General Herron, which was placed on our left. This cut off the last possible chance of communication between Pemberton and Johnston, as it enabled Lauman to close up on McClernand’s left while Herron intrenched from Lauman to the water’s edge. At this point the water recedes a few hundred yards from the high land. Through this opening no doubt the Confederate commanders had been able to get messengers under cover of night.