at Port Hudson with one or two regiments, with a view of attacking our forces on the Plaquemine or the La Fourche.
RICH'D B. IRWIN.
Lieutenant-Colonel, Assistant Adjutant-General.
HEADQUARTERS RESERVE BRIGADE,
Camp Stevens, near Thibodeaux, La., January 6, 1863.
Major General N. P. BANKS,
Commanding Department of the Gulf, New Orleans:
GENERAL: When the expedition under my command which resulted in the capture of this district was first contemplated I suggested to General Butler the idea of employing some of the funds which were in his possession to construct some light-draught gunboats to co-operate with me by the way of Berwick Bay. The suggestion was adopted, and these boats (four in number), commanded by naval officers, only failed in consequence of a strong northwest to hem in the rebel forces, and the capture of the entire force of the latter was thus prevented. The rebels crossed Berwick Bay and their gunboat (the Cotton) escaped into the Teche, and she has since lain securely an obstruction placed in the Teche below her.
As our force was so small in the department at the time, and I could not get sufficient force to secure my lines of communication with New Orleans, General Butler, would not order me to cross Berwick Bay. There was nothing to be gained either by such an operation, except by covering the gunboats in removing these obstructions to secure the rebel gunboat Cotton, as the rebel land forces had a clear and open line of retreat and moved faster than we could.
Since my occupation these four gunboats have been kept, as at first intended, in Berwick Bay, and have rendered efficient service in cleaning the bay and the highly important adjacent waters of rebel craft, and have securely and effectual protected my left flank.
All suggestions and opinions I have made to you with reference to the position and the strength of the forces which would be necessary to hold this district were based upon the supposition that these gunboats would be kept in the waters where they now are. To-day I hear from Lieutenant Comdg. T. McK. Buchanan, who commands the whole gunboat fleet, that one them, the Estrella, has been ordered to Galveston; that his own vessel the Calhoun, will in about a month be compelled to go to New Orleans for repairs which will require six weeks to complete and that he has discretionary orders to send another of these boats to the sound and Lake Pontchartrain to replace the New London, which has been ordered to Galveston.
The admiral has this power to order these vessels, because your chief quartermaster has turned them over to the Navy.
Now I consider it my duty to inform you that if the Navy, by means of these gunboats, does not keep undisputed possession of Berwick Bay and the adjacent waters the force here will have to be greater than I represented to you. That these waters are of the highest importance to the rebels; that by gaining possession of these waters by means of the numerous light-draught boats now hidden in the adjacent bayous and streams they could make frequent raids, which no force of ours on land could prevent;that they could run the blockade, as they frequently did before we occupied it; that by holding these waters we threaten