[Inclosure.]

U. S. Mississippi SQUADRON,

Flag-Ship Black Hawk, off Vicksburg, July 13, 1863.

Honorable GIDEON WELLES, Secretary of the Navy, Washington, D. C.:

SIR: The want of steam transportation in the army is very much felt. The Marine Brigade consists of a large number of vessels, capable of transporting 10,000 men. I would recommend that the brigade and vessels should be turned over to the commander-in-chief of the Army of the Tennessee, Major General U. S. Grant, who should properly direct all military movements here. I find the Marine Brigade and army do not get along very well together when co-operating. I would, therefore, recommend that General Grant should take charge of the whole concern, excepting the ram fleet, which should be turned over to the Navy for transports. They are mostly worn out and are run at great expense.

The brigade as it is now is so small that it is not available against the bodies of guerrillas which infest the Mississippi. If it is placed under General Grant's orders altogether, he can use the vessels to throw into any place a body of 10,000 men. I have offered to order the brigade to report to him for what duty he may wish to assign it, but he would prefer to have it placed entirely under his control, that he may make permanent arrangements with regard to a proper organization. At present there are a good many complaints about the Ellet Marine Brigade, which, whether true or not, seem to require that a better organization should exist.

I recommend most urgently that I may be ordered to transfer the brigade and vessels permanently to the Army, and that an order may be received from the War Department to deliver up to the Navy the rams, to be used as transports, or else to have them turned over to the quartermaster's department of the army, where they are much needed. General Banks has just called for twenty steamers, and General Grant has to curtail his transportation to comply with the request. The brigade is at present employed at a distance, and the whole effective force is about 500 men. If the army had the steamers, they could make better use of them.

I have the honor to remain, very respectfully, your obedient servant,

DAVID D. PORTER.

SPECIAL ORDERS, HDQRS. DEPARTMENT OF THE TENNESSEE Number 207. Vicksburg, MISS., July 31, 1863.

VI. The NINTH Army Corps, Major General J. G. Parke commanding, will return to the Department of the Ohio as rapidly as transportation can be provided. On arriving at Cairo, General Parke will telegraph to the General-in-Chief of the army and to Major-General Burnside for further instructions.

The provost-marshal-general of this army will send north all prisoners of war not authorized to be paroled, in charge of the NINTH Army Corps. They will be left at Indianapolis, or such other point as the General-in-Chief may direct.

In returning the NINTH Army Corps to its former command, it is with pleasure that the general commanding acknowledges its valuable services in the campaign just closed. Arriving at Vicksburg opportunely, taking position to hold at bay Johnston's army, then, threatening the forces investing the city, it was ready and eager to assume the aggressive at any moment. After the fall of Vicksburg, it formed a part of