FLAG-SHIP BENTON, New Carthage, April 20, 1863.

Major General U. S. GRANT, Commanding,&c.:

GENERAL; I sent the Tuscumbia and Price down to Grand Gulf to reconnoiter to-day and destroy flat-boats, and the following is the result:

The rebels are at work fortifying. Three guns are mounted on a bluff 100 feet high, pointing up river. Two deep excavations are made in the side of the hill (fresh earth); it cannot be seen whether guns are mounted on them or not. About thirty tents only could be seen, but a heavy dust on the road leading along Big Black. Covered wagons were traveling on the road; four boats, 12 miles up Big Black, at a bridge which stops the way; they are small boats. The officers landed on the Louisiana side, where they found horses, cattle, mules, fowls, and provisions of all kinds in great abundance; large amount of forage; plenty of negroes; 300

beef-cattle on one plantation; people running in all directions, and driving off the negroes and cattle. My opinion is that they will move heaven and earth to stop us if we don't go ahead. I could go down and settle the batteries, but if disabled would not be in condition to cover the landing when it takes place, and I think it should be done together. If the troops just leave all their tents behind and take only provisions, we can be in Gulf in four days. I don't want to make a failure, and am sure that a combined attack will succeed beautifully. I think 10,000 good men leading in Vicksburg the other night would have taken it; we can do this easier. This move has demoralized these fellows very much; don't give them time to get over it. I wish twenty times a day that Sherman was here, or yourself, but I suppose we cannot have all we wish. I have been working hard on barges; got the tug to Smith's Landing with a fine one to-day; picked up another last night, which will go up to-morrow, and will also send the largest one of all to Smith's before sundown. We can, with the steamers and barges, land 6,000 men, if you think that enough; if we can get more transports, it will be better. The best way to send them down is to left them drift under low fires, and push by one at a time, half an hour apart, if they build no fires to light up the boats; should not be too close together. I would not pack them with cotton, but with wet hay, which proves an excellent defense. You will find volunteers enough in my squadron if you have any trouble, and the steamer men can come down afterward.

Very truly,

DAVID D. PORTER.

HEADQUARTERS THIRTEENTH ARMY CORPS, Smith's Plantation, April 20, 1863.

Major General U. S. GRANT, Comdg. Department of the Tennessee:

GENERAL: The Forest Queen arrived last night in a shattered condition. I am unloading the commissary and quartermaster stores from her. General Osterhaus' DIVISION will be on the Mississippi levee to-night. He is moving his DIVISION down to Perkin's plantation, for the purpose of making room for the disembarkation of General Carr, which will commence being crossed over in the morning.

I have just brought to this place one large barge, and expect to bring others in the morning, which will hasten the transportation of General Carr's DIVISION.

I sent Colonel Wright and Lieutenant Hains, engineers, down the Vidal this morning, to examine whether a land route might be found