SPECIAL ORDERS,
HDQRS. DEPT. OF THE TENNESSEE,

Numbers 205.
Vicksburg, Miss., July 29, 1863.

I. The Thirteenth Army Corps, Major General E. O. C. Ord, commanding, will be held in readiness to move to and take post at natchez, Miss., as soon as transportation can be furnished.

On the arrival of one division of the Thirteenth Army Corps at Natchez, the troops now there will return to Vicksburg.

The commander at Natchez will be charged with keeping the river open to navigation from Rodney, Miss., to the Louisiana and Mississippi State line.

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By order of Major General U. S. Grant:

T. S. BOWERS,

Acting Assistant Adjutant-General.

Major General H. W. HALLECK,

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

GENERAL: I have satisfactory information that the rebels have abandoned the country as far north as Alexandria, with the exception of a small corps of observation near Franklin. Our forces took possession of Brashear City some days since. There is no enemy of any force now in the department south of Alexandria. It is believed that the force which has occupied the La Fourche district is moving northward and westward toward Natchitoches or Shreveport, with a view of joining Kirby Smith at that place. A small force, with a few light-draught gunboats, will be able to keep this district clear. The navigation of the river has been undersigned this side of Port Hudson. A few guerrillas are heard of above, but nothing to obstruct the successful navigation of the river for our transport vessels. The nine-months' regiments are being transported to the north by sea and by river as rapidly as our transportation will admit. We lose twenty-two regiments, leaving about 12,000 effective men in this department.

Information from Mobile leads us to believe that the force at that point is now about 5,000, engaged industriously on the land side in strengthening the position. My belief is that Johnston's forces are moving to the east, and that the garrison will not be strengthened unless it be paroled men from Vicksburg or Port Hudson. While the rebel army of the east is occupied at Charleston and at Richmond by our forces, it would be impossible for them to strengthen Mobile to any great extent. It seems to be the favorable opportunity for a movement in that direction. The attack should be made by land. troops can be transported up the river to Mobile, with the intervention of a march of 25 miles from Portersville on the west side of the bay to the rear of the city. we have outlines of their works and can estimate very well their strength. I am confident a sudden movement, such as can be made with 20,000 or 25,000 men on this point, will reduce it with certainly and without delay. The troops of the west need rest, and are incapable of long or rapid marches. It is, therefore, impracticable to attack Mobile except by the river and Mississippi Sound. A portion of General Grant's force could be transported there with but little labor to