railroad mentioned. The map shows two roads leading from a point a short distance below the mouth of Bayou Pierre; one to Grand Gulf and the other to Port Gibson. The object is to ascertain whether the flank or rear of the enemy's position at General Gulf may be gained by our forces moving either by land or water from the vicinity of the mouth of Bayou Pierre. It is not expected that you will push your reconnaissance and undue distance below a point opposite Bayou Pierre. As it is understood that the rebel Colonel [I. F.] Harrison, with an estimated force of from 400 to 700, is hovering about or near the route of your contemplated march, youand capture or disperse his force.

It is left with you to determine whether you will take the whole or only a portion of your DIVISION with you, and for you to decide whether you will or will no take your artillery or any portion of it. Take ammunition, and (if you think it unsafe to rely on the country for provisions) rations also, either in wagons or haversacks. Leave everything else behind that will necessarily encumber you, under the protection of a guard. Reports as often as practicable, so that I may determine whether it will be best to recall you from your destination, or leave you there, to be followed by the rest of the corps.

With respect, sir, your obedient servant,

JOHN A. McClernand.

P. S. -Take the SECOND Illinois Cavalry with you, if you thin proper. It is at Perkins'.

SMITH'S PLANTATION, April 24, 1863.

Brigadier General PETER J. OSTERHAUS:

GENERAL: This order will take the place of the one sent to-day for a reconnaissance down the river. You will send all the cavalry at Perkins' plantation, including any that General Carr can spare, to make the contemplated reconnaissance. You will also send two regiments of infantry, with the cavalry, for the same purpose. You will hold in readiness for prompt embarkation upon notice. An early attack upon Grand Gulf is anticipated. Prepare for participating in it.

One, and an important, object of the reconnaissance is to ascertain whether there is a practicable road from Perkins' to a point opposite or nearly opposite to Grand Gulf from which troops might be crossed to the east bank of the river, and thence marched upon that place. The nearer the point from which to effect such crossing the better, as it is intended that the troops to be crossed will participate in the contemplated attack upon Grand Gulf. If no such point can be found nearer that place than opposite the mouth of Bayou Pierre, the reconnaissance will be extended that far, and, if necessary, still below, within safe distance.

All instructions contained in my previous communication upon this subject not inconsistent herewith will be observed by the detachment hereby authorized.

Immediately upon completing the contemplated reconnaissance, the detachment will return to Perkins' plantation, and, there, encamping, guard all the approaches to that place until further orders.

Your obedient servant,

JOHN A. McClernand.

P. S. -If you think it necessary, you may send a section of artillery with the detachment.