About the same time the formation of a regiment of engineer troops was undertaken, composed of picked men of color, formed in three battalions of four companies each, under white officers carefully chosen from among the veterans. The ranks of this regiment, known as the 1st Louisiana engineers, were soon recruited to above a thousand; the strength for duty was about eight hundred. Under the skilful handling of Colonel Justin Hodge it rendered valuable service throughout the siege.
Company K of the 42d Massachusetts, commanded by Lieutenant Henry A. Harding, had for some months been serving as pontoniers, in charge of the bridge train. During the siege it did good and hard work in all branches of field engineering under the immediate direction of the Chief Engineer.
While at Opelousas, Banks had applied to Halleck to order Brigadier-General Charles P. Stone to duty in the Department of the Gulf. Stone had been without assignment since his release, in the preceding August, from his long and lonely imprisonment in the casemates of the harbor forts of New York, and, up to this moment, every suggestion looking to his employment had met the stern disapproval of the Secretary of War. Even when in the first flush of finding himself at last at the top notch of his career, Hooker, in firm possession, as he believed, of the post he had long coveted, as commander of the Army of the Potomac, had asked for Stone as his Chief of Staff, the request had been met by a flat refusal. A different fate awaited Banks's application. On the 7th of May Halleck issued the orders asked for, and in the last days of the month Stone reported for duty before Port Hudson. At first Banks was rather embarrassed by the gift he had solicited, for he saw that he himself was falling into disfavor at Washington; the moment was critical; and it was easy to perceive how disaster, or even the slightest check, might be magnified in the shadows of Ball's Bluff and Fort Lafayette. Moreover, Stone was equally unknown to and unknown by the troops of the Nineteenth Army Corps. Instead, therefore, of giving him the command of Sherman's division, for which his rank indicated him, Banks kept Stone at headquarters without special assignment, and made every use of his activity, as well as of his special knowledge and ready skill in all matters relating to ordnance and gunnery.