As chief of ordnance during the American Civil War, Gorgas managed to keep the Confederate armies well supplied with weapons and ammunition, despite the Union blockade, and even though the South had hardly any munitions industry before the war began. In this effort he also worked closely with the Fraser, Trenholm shipping company that brought in shipments of ordnance by means of blockade runners. He kept diaries during the Civil War which are now a popular subject of study for historians.