I will move forward by 6 o'clock in the morning, and at least feel the enemy. It is very desirable that McPherson should at the same time move forward upon Edwards Station, on the north side of the railroad, and cut off the enemy if I should drive him from his position. Broken bridges may delay the movement on both sides of the railroad.

I have heard nothing of the general supply train. May I rely on it, or shall I send back the entitled teams of the regiments to Grand Gulf?

If so, will there be troops on the way to protect them?

General Osterhaus has just captured a letter written by a rebel captain in Vicksburg, in which he says that on the 10th instant the rebel force there was 40,000, and estimates our force at 70,000.

JOHN A. McClernand.

BOLTON, MISS, May 15, 1863.

Brigadier General CARR, SMITH, HOVEY, and OSTERHAUS:

The following will be the order of movement to-morrow as near as may be:

General Blair will move on the road first, diverging to Edwards Station from the Raymond and Bolton road, about 1 1/2 miles this side of Raymond, and will form the left wing.

General Osterhaus will move on the next road to Edwards Station, diverging about 3 miles this side of Raymond, and will form the center.

General Carr will move up to, and then on, the same road with General Osterhaus, and as a reserve.

General Hovey, will move on or near the road on the south side of the railroad from Bolton to Edwards Station.

Each of these DIVISIONS will move promptly at 6 o'clock in the morning, except General Blair's, which will move at 5, and will leave the baggage trains in the [rear], or otherwise dispose of them, so that they will be out of the way.

The movement will be toward Edwards Station, with the purpose to feel the enemy and to engage him if it be found expedient to do so.

Let each DIVISION keep up communication with that or those next to it, and all move on parallel with each other as near as may be. It is expected that General Smith will be up in time to co operate with General Blair on the left. It has been asked that General McPherson be directed to move forward from Bolton, on the north side of the railroad, so as to cut off the enemy's escape. Let every arm be furnished with adequate ammunition. Straggling from the lines should be prevented. I will be found near the center of the line of advance. DIVISION commanders will communicate with me often.

JOHN A. McClernand.

JACKSON, MISS., May 15, 1863.

General MOWER,

Commanding Post of Jackson:

DEAR GENERAL: We will march for Bolton, via Mississippi Springs, to-morrow noon.

Push the work of destruction, especially of types, presses, sugar, and everything public not needed by us. The work should be all done by 10 a. m. to-morrow.

You will move at 1 p. m., bringing up the rear. Don't mention the