BANKS, Major General Commanding, to Henry W. Halleck, December 9, 1863

General Banks to General H. W. Halleck.

General: I beg leave to submit, upon the subject referred to in the accompanying papers, relative to the detention of the British vessel H. G. Berry, the following report. All the facts stated therein were within my knowledge, except that which relates to the information being conveyed by the schooner; but I have no doubt whatever of this. The times and circumstances of the arrival of that vessel make it impossible that the information could have been otherwise conveyed.

A full statement of the vessel’s forces, guns, &c, the losses sustained on the voyage, was sent to a rebel officer in Matamoras, and received there on the evening of the day that my troops occupied Brownsville. Of this fact I have positive knowledge. Had it been received earlier by the rebels, it would have prevented their evacuation, and might have defeated our landing at Brazos Santiago. If this had occurred, the expedition would have failed. The person who gave this information called upon me as a Texan refugee, and offered to procure information in regard to the armament and defences of Fort Brown. The circumstances detailed to me at Matamoras make this certain: the information as to our forces was conveyed to the rebels by this schooner, either by passenger or letter, and her detention by my order caused the delay in its transmission, which enabled the forces of the United States to occupy the position in advance of the reports of this spy. The information in regard to our fleet and forces was obtained at New Orleans; the. report of our losses, at the Eio Grande. Of these facts I have no doubt whatever. It is not probable that the owners of the vessel were parties to the treason.

I have the honor to be, with much respect, your obedient servant,