Mobile had a ship-building industry even before the war, but by 1864 it had become a significant center for Civil War factories. The CSS Baltic, Gaines, and Morgan were built in Civil War factories on the river front at Mobile–key assets to Confederate Civil War strategies. The CSS Tennessee was built primarily at Selma but was floated down the Alabama River and finished at Mobile. The City also had one of the few torpedo factories during the Civil War. Finally, more torpedo boats and submarines were tested at Mobile than anywhere else in the South. The CSS Hunley was built in Mobile and tested in the Bay before it was shipped to Charleston where it sank the USS Housatonic in 1864.
"An infernal machine, consisting of a submarine boat, propelled by a screw which is turned by hand, capable of holding five persons and having a torpedo which was to be attached to the bottom of a vessel and exploded by means of clockwork, left Fort Morgan at 1 p.m. in charge of the Frenchman who invented it. The intention was to come up at Sand Island, get the bearing and distance of the nearest vessel, dive under again and operate on her; but on emerging found themselves so far outside of the island and in so strong a current that they were forced to cut the torpedo adrift and make the best way back. The attempt will be renewed as early as possible, and three or four others are being constructed for that purpose."