already the flag-ship Hartford, the gunboat Albatross, and therm Switzerland. Two of our gunboats-the Estrella and Arizona, which I sent up the Atchafalaya-are also with the admiral.

Our advance marched on Alexandria yesterday morning and the main body moved this morning. I had previously given orders to break up our depots on the Teche and Courtableau, expecting to have our communications by the Atchafalaya and Red River. I anticipate but little serious resistance to our advance. Our naval force is sufficient to destroy that of the enemy, who, inferior in numbers and broken down in morale, will not, I think, attempt to make a stand against us. If he does we shall beat him. Providence once more smiles upon our arms.

I have the painful duty of reporting the murder of Captain Howard Dwight, assistant adjutant-general, serving at these headquarters, by a party of guerrillas yesterday afternoon, while riding to the front to join the advance. I have ordered Brigadier-General Dwight, commanding the advance, to arrest 100 of the while male persons in the vicinity of the scene of the murder and to send them to New Orleans, there to be kept in close confinement as hostages for the delivery of the assassins into the hands of the artillery authorities of the United States. The people of the neighborhood who harbor and feed those lawless men are even more directly responsible for the crimes which they commit, and it is by punishing them that this detestable practice will be stopped. Retaliation by executing great numbers of our prisoners does not meet the case, for, aside from graver objections, these are, in our case men tired of war and anxious, at the first opportunity, to lay down their arms, and in many cases even by taking the oath of allegiance, to escape from further service. To retaliate upon them would be a greater injury to us than to the enemy, who, indeed, is in the habit of holding out the prospect of maltreatment by us an inducement to his men not to desert.

Very respectfully, your obedient servant,

N. P. BANKS,

Major-General, Commanding.

Major General H. W. HALLECK,

General-in-Chief, Washington, D. C.

[Inclosure.]

FLAG-SHIP BENTON, May 4, 1863.

Major General N. P. BANKS,

Comdg. Nineteenth Corps, Dept. of the Gulf:

GENERAL: I shall start from here in an hour for Alexandria, and will co-operate with you with a large force of gunboats. I have just left Grand Gulf. The batteries there (very heavy ones) fell into our hands after a hard fight with the gunboats of five and a half hours.

General Grant was on the Mississippi side with 36,000 men and much artillery. He was driving the rebels before him when I left; had sent in 400 prisoners and captured six guns. He had a fight, in which the rebels lost many killed and wounded.

Sherman will pass over into Mississippi in a day or two, and our effective force is or will be 50,000 men. The taking of Vicksburg is a mere matter of time. They will likely evacuate it.

I remain, respectfully,

DAVID. D. PORTER,

Acting Rear-Admiral.