ok. He was engine room crew (fireman) aboard the transport/gunboat J.F. Carr. The date of June, 1863, suggests that he was part of the original crew when the Carr was converted to a gunboat. She had been comandeered from her owners to carry backup troops during the Battle of Galveston in January, 1863, but didn't get into the action at that time. Carr ended up working the Matagorda Bay-Corpus Christi area in 63 and 64. She shows up as one of the surrendered vessels at Galveston in June of 65. He was detached, so consider him "loaned". In theory, his original unit still owned him. Many of the steamer crews were actually civilians and "exempt" from military service in terms of being conscripted. The gun crews and sharpshooters were put aboard when action was anticipated and used regular Army personnel. This caused some heartburn with the Army regulars who believed the Marine Departments "exempt" types had it much better than the troopers. If I'm reading this correctly, he was technically still in the Army, but assigned as a skilled occupation aboard the steamer and under the Marine Department (Quartermaster Department). Do you have any idea whether he volunteered or was just ordered to the Marine Department? There is at least one other case like this, a trooper from one of the units at Sabine Pass was assigned aboard a former Union gunboat converted into a runner as an engineer.