Do you think Johnston is receiving re-enforcements, or is he simply holding Jackson until the road east of him is completed, so that he can get off all the rolling stock on this side? Can you make a safe retreat to the Big Black, if it is found Johnston is receiving re-enforcements from the east?
I would not advise your infantry going any farther east than they are, except you should find it advantageous to hasten the retreat of the enemy. Should you find it impossible to drive Johnston from his position, and your remaining endangers either it or this place, you can then return.
I have sent Mower's brigade and one brigade from Kimball's DIVISION to relieve McArthur, and ordered the latter forward. The remainder of Kimball's DIVISION is still disposable, but there is no other force here to spare well. I send this by Captain Audenried, of my staff, who will remain with you a day or two.
An intercepted letter from Jeff. Davis to Lee was sent me from Washington. From that it would seem that Lee has been asking for Beauregard to be sent to Culpeper Court-House with an army of 30,000. Davis speaks of the impossibility of doing so, and says Johnston is still calling for more re-enforcements, though his first requisition had been more than filled. He does not say whether he will still send more troops west, but from alarm expressed in the letter for the safety of Richmond, I judge Johnston can expect nothing more.
Captain Audenried will give you any news there is here.
U. S. GRANT.
Vicksburg, MISS., July 13, 1863.
McArthur left Black River at 5 this morning. Mower's brigade and one of Kimball's relieved him.
I have written to Banks to send Grierson up, but do not believe he will send him.
Ransom has gone to Natchez to destroy ferries and bring up beefcattle collected for Johnston.
Herron has gone to Yazoo City to break up that place. On his return, I will send you Kimball's DIVISION, if you want it.
U. S. GRANT.
SPECIAL ORDERS, HDQRS. SEVENTEENTH ARMY CORPS, Number 137. Vicksburg, MISS., July 13, 1863.
II. Brigadier General J. C. Sullivan having reported to the major-general commanding, is temporarily assigned to duty as chief of staff of this corps, and will be respected and obeyed accordingly. This order will be operative from July 4, 1863.
By order of Major-General McPherson:
WM. T. CLARK,
HDQRS. EXPEDITIONARY ARMY, July 13, 1863.
Brigadier General J. McARTHUR, Comdg. DIVISION, Champion's Hill:
DEAR GENERAL: I want to give Johnston a good shelling as soon as I can afford the ammunition, and have sent down a train to bring up