I cannot close this hasty dispatch without expressing my admiration at the good conduct of my officers and men in the affair of Sunday before Fort Bisland and in the battles of Fort Bisland and Irish Bend. I shall take occasion to ask you attention to individual instances of merit hereafter, but I desire now to bring to your special notice the services of the commanders, Brigadier-Generals Emory, Grover, and Weitzel, to whose zealous co-operation, professional skill, and devotion on the battle-field we are lately indebted for the success of the expedition.

Great credit is due to the energy and efficiency shown by the offices of the Navy in this operation.

The country abounds in supplies of all kinds, which I shall apply to the utmost to the purposes of the Government.

Our loss is small, but as we have made hard marches every day and only halted at night it has been impracticable to get exact figures.

I have the honor to be, very respectfully, your obedient servant,

N. P. BANKS,

Major-General, Commanding.

Major General H. W. HALLECK,

General-in-Chief.

No. 11.] HDQRS. DEPT. OF THE GULF, 19TH ARMY CORP Opelousas, La., April 23, 1863.

GENERAL: Since my Nos. 9 and 10, of the 17th instant, I have had neither time to prepare formal dispatches nor, until now, convenient opportunity for sending them. I have, however, endeavored to keep you constantly advised of your movements and their results by telegraph through General Sherman, commanding at New Orleans.

On the evening of the 17th General Grover, who had marched from New Iberia by a shorter road and thus gained the advance, met the enemy at Bayou Vermillion. The enemy's force consisted of a considerable number of cavalry, about 1,000 infantry, and six pieces of artillery, masked in a strong position on the opposite bank, with which we were unacquainted. the enemy was driven from his position, but not until Everything had been previously arranged for this purpose. The enemy's fight was precipitate.

The night of the 17th and the whole of the next day were occupied in pushing forward with vigor the reconstruction of this bridge.

On the 19th the march was resumed and continued to the vicinity of Grand Coteauy, and on the following afternoon our main force occupied Opelousas, the cavalry, supported by one regiment of infantry and a section of artillery, being thrown forward to Washington, on the Courtbleau, a distance of 6 miles. The command rested on the 21st.

Yesterday morning (the 22nd) I send out Brigadier-General dwight, with his brigade of Grover's division nd detachments of artillery and cavalry, to push forward through Washington toward Alexandria. He found the bridges over Bayous Cocodrie and boeuff destroyed, and occupied the evening and night in replacing them by a single bridge at the junction of the two bayous. The people say that the enemy threes large quantities of ammunition and some small-arms into Bayou Cocodrie, and that the Texans declared they were going to Texas. Here the steamer Wave was burned by the enemy, and the principal portion