Iowa Infantry, commanded by Captain Adams, 320 men; a part of the Twenty-sixth Indiana Infantry, Lieutenant-Colonel Rose, 346 men; one section of Battery E, First Missouri Light Artillery, Second Lieutenant E. S. Rowland, 28 men; detachments of Sixth Missouri, Second and Thirty-sixth Illinois Cavalry, under Major Montgomery, 160 men. The whole being under command of Lieutenant Colonel J. b. Leake, Twentieth Iowa Infantry.

Lieutenant-Colonel Leake's instructions from Major-General Herron were to keep the country well reconnoitered; to keep his cavalry constantly out; to push daily reconnaissances toward the Atchafalaya, where a considerable force of the enemy were posted, and frequently to push his advances up to the river, and annoy the enemy's pickets and drive them in. The morning after I assumed command (yesterday), I dispatched a courier with an escort to Lieutenant-Colonel Leake, with orders, &c.; two wagons loaded with knapsacks belonging to his command were sent out with a small infantry guard.

The weather had been stormy during the preceding afternoon and night, and the rain was still drenching and the road bad. Soon after noon, a messenger came back from the wagons, with information that the road was in possession of a strong force of the rebels, about half-way to Lieutenant-Colonel Leake's camp; that the guard had skirmished with them, and had held their front, supposed to be Lieutenant-Colonel Leake clearing the road. I immediately ordered Colonel Black, Thirty-seventh Illinois Infantry, to march with his regiment to open the communication, and to assume command of his own and Lieutenant-Colonel Leake's troops, and be governed by circumstances, pursuing the enemy and punishing him as much as possible.

The road was bad and heavy for marching, and the rain was drenching, and when Colonel Black had proceeded 3 miles, he met Major Montgomery with his cavalry detachment, and from him and stragglers he learned that the enemy had attacked Lieutenant-Colonel Leake's command on all sides at once; had surprised him by coming through the cane and corn fields of the country, as well as by the road, and by first opening the attack in the rear, and being dressed in United States uniforms.

Major Montgomery's command checked the enemy, and escaped with the loss of 5 missing, and brought off 6 prisoners; but as the enemy was pushed in between his force and the infantry, he failed to effect a junction, but supposed the infantry force had been captured.

Colonel Black took a strong position in line of battle, and remained there till after dark, when, at 7 o'clock, an officer bearing a flag of truce from the enemy made his appearance with the following dispatch:

BAYOU FORDOCHE,

September 29, 1863.

Major-General HERRON,

Or Commander of Forces at Morganza:

GENERAL: I send to you a flag of truce by Captain Breaux, the object of which he will explain. Considering it anb act of humanity, the brigadier-general commanding has instructed me to send you this message: That you have many wounded and dead, which he cannot bury or care for, and, if it meets with your approval, hostilities will be suspended for twenty-four hours, to allow you to take care of the wounded and dead. The general also instructs me to say that he has left your surgeons and steward to attend on them.

By order of Brigadier General Thomas Green:

Very respectfully,

W. B. RATLIFF,

Captain, Commanding Post.