I received the following letter from Gen. McClernand,
HEADQUARTERS THIRTEENTH ARMY CORPS, Milliken’s Bend, La., April 13, 1863.
Major General U. S. GRANT, Comdg. Department of the Tennessee:
GENERAL: I think the contemplated expedition ought not to take less than 300 rounds of ammunition per man, which would give a total of 6,000,000 rounds for a force of 20,000 men. Deducting from this sum 60 rounds per man, to be carried by the soldier, the balance would be 4,800,000 rounds.
To transport this amount of ammunition 35 miles by land, from here to Carthage, would require three days in the present miry state of the roads, and 300 wagons. Not having more than 150 wagons that can be made available, it would require eight days to transport it, including two of one return trip. To transport 300 rounds per gun for ten six-gun batteries of different caliber, would require three days and at least 90 wagons, making in all for the transportation of both infantry and artillery ammunition thirteen days, including four days for two return trips.
To obviate this delay and to hasten the important movement in view, I would earnestly recommend that the estimated supply of ammunition for all arms be sent down in one or more gunboats. If the gunboats cannot be made available, then I would recommend that a transport be lade with ammunition and sent down. To avoid accident, I would place two barges filled with wetted baled cotton, so as to shield the bow on the exposed side and the stern of the transports; and if, notwithstanding this precaution, the cotton should be ignited by the fire of the enemy, the transport might be cut loose, and thus enabled to escape destruction.
Your most obedient servant,
JOHN A. McClernand.
P. S. -I would inquire whether some of the transports intended to run the blockade might not be used to carry camp and garrison equipage, and thus further relieve the land movement across to Carthage, over the worst possible road since the recent rains, o encumbrances and delays.
Millikens Bend, La
April 13, 1863
Maj Gen J. A McClernand Comm’dg 13th Army Corps
I am having a complete map of the East bank of the Mississippi made for you, showing all the Streams and roads from Port Hudson to Vicksburg. I sent you a guide yesterday.
Instructions which I sent to your Headquarters and which you could not yet have received answers most of your note. It is not desirable that you should move in any direction from Grand Gulf, but remain under the protection of the Gunboats and free all the transportation for the concentration of troops at that place. The present plan if not changed by the movements of the enemy will be to hold Grand Gulf Send a force to cooperate with Banks to effect the reduction of that place and then move upon Vicksburg either by reaching Big Black Bridge or Jackson Miss.
If you should not return to the Bend, I will endeavor to see you at Carthage before you leave.
Make every facility you can for moving troops from Smiths plantation to Carthage and for shipping them there get all the ammunition you can through Until water communication is open with Carthage there will be more difficulty in getting through this supply than any other. I have explained in a former communication that provisions will be sent by the transports that run the blockade.
U. S. Grant
The Papers of Ulysses S Grant, Vol 8, p 63-4
National Archives, RG 393, Dept. of the Tenn., Letters Sent;
O.R., I, xxiv, part 3, 190