[Inclosure.]

HDQRS. DEPT. OF THE GULF, NINETEENTH ARMY CORPS,
Camp at Brashear City, La., April 10, 1863.

Major General U. S. GRANT,

Commanding Department of the Tennessee:

GENERAL: The secretary of Admiral Farragut, Mr. Gabaudan, called upon me at Bashear city this morning and gave me the substance of your dispatch. We have 15,000 men that can be moved with facility. The artillery is strong, the cavalry weak, but we hope to strengthen the cavalry without delay, as one of the results of this expedition.

We shall move upon the Bayou Teche to-morrow, probably encounter the enemy at Pattersonville, and hope to move without delay upon Iberia, to destroy the salt-works, and then upon Opelousas. This is the limit proposed. We do not intend to hold any portions of this country, as it weakens our force, but will at once return to Baton rouge to co-operate with you against Port Hudson. I can be there easily by May 10.

there are now 4,500 infantry at Baton Rouge, with three regiments of colored troops and two companies of cavalry, three batteries of artillery, with several heavy guns in position, and five gunboats and six mortars. The land force is under command of Major-General Augur; the fleet under Captain Alden, of the Richmond.

We shall endeavor to establish communication with Admiral Farragut near Bayou Sara, but the opening of the levee opposite Port Hudson may make it impossible. If so, we will communicate with you freely, by the way of New York, as to our progress. I shall be very glad if you will communicate with us in the same manner. To avoid delays by mail I will send my dispatches by an officer.

Very respectfully, your obedient servant,

N. P. BANKS,

Major-General, Commanding.

No. 10.] HDQRS. DEPT. OF THE GULF, 19TH ARMY CORPS Bouligny's, beyond New Iberia, La., April 17, 1863.

GENERAL: I have the honor to inform you that we set out on the 11th instant upon the expedition, the preparations for which were temporarily interrupted by the necessity for co-operation with the Navy in the passage of the fleet by Port Hudson.

With Emory's division, Weitzel's brigade, of Augur's division, and the siege train I crossed Berwick Bay on the 9th, 10th, and 11th, and marched on the morning of the 12th upon the enemy, strongly entrenched at Fort Bisland, about 4 miles beyond Pattesonville. The enemy's force was about 5,000, including three batteries of artillery and a heavy proportion of mounted troops from Texas.

We met the enemy about 2 o'clock in the afternoon, and after brisk engagement drove him back until his line of defense was revealed, and took up a position which enabled us to reconnoiter his works to advantage. Here night interrupted us.

Early the next morning the attack was resumed. We soon drove him into his works and advanced upon them, keeping up a heavy fire of artillery to silence his guns and prepare the way for an assault. At night-fall we had disabled the gunboat Diana and driven her out of action, almost entirely silenced the enemy's artillery, and advanced on both sides of the bayou to within about 400 yards of the works.