I hope to concentrate, with your corps, 20,000 men. Our great want will be in cavalry. If you can send us any assistance in this, I shall be greatly indebted. General Grierson expressed a strong desire to join us in this expedition, but it opens sooner than either of us expected. If he can be spared, I hope he will be permitted to join us. I forward a dispatch to him way of information. Cavalry is of the highest importance in the country to which we are ordered.

I am sorry that I cannot now send transports to expedite General Ord's movements. The steamers sent north not yet returned. We have not one to send you, but, as soon as they arrived, will urge them forward.

The vessels fit for sea navigation only can be used by us in this expedition. If you can spare any of the tug-boats temporarily, I shall, be greatly obliged, and will return them as soon as they can be spared. We shall be compelled to use sailing vessels, from the defenciencies of our transportation.

I will keep you advised of all our movements, and shall be indebted to you for any suggestions which you make upon the matter in hand.

I am, general, with regard, your obedient servant,

N. P. BANKS,

Major-General, Commanding.

[P. S.]- Light-draught tin-clads, of which there are many on the upper river, as I am informed by Commodore Graham, will be of great service to us in the waters connecting with New Orleans. If they can be spared, I beg you to sent them to us without delay.

NEW ORLEANS, LA., August 16, 1863,

VIA CAIRO, ILL., August 24.

Major-General HALLECK,

General-in-Chief, U. S. Army:

It is necessary that three or four steamers should be sent us from New York without delay. If they are need for public service, the steamers on the way to new York from New Orleans can be substituted for them. I beg you to give an order to the quartermaster at new York to that effect. We shall not await their arrival, but we shall need their assitance.

N. P. BANKS,

Major-General.

HDQRS. DEPT. OF THE GULF, NINETEENTH ARMY CORPS,
New Orleans, August 16, 1863.

Admiral DAVID D. PORTER,

Or the Officer Commanding the Fleet at Vicksburg:

SIR: It is probable that a movement will be undertaken from New Orleans which will draw most of the forces from that city. To prevent an invasion of the Texas troops, it will be necessary that the Atchafalaya River and Berwick Bay should be patrolled by light-draught gunboats. If you have a half dozen light-draught tin-clads that you can send into these waters, it will be of great service to us. None of our gunboats will pass Lake Chicot, as they draw over 6 feet of water. If