 The only exception was at the Siege of Vicksburg where the army, marching downstream met up with the Union Navy under Rear Admiral David Farragut sailing upstream and the two combined their forces for an all-out land-and-sea shelling of the town.The river campaigns saw the first practical use of river gunboats and river ironclads, in particular the City-class ironclads, ironclad paddle steamers built by James B. Eads in St. Louis and Cairo, Illinois.It also saw the use of sea mines, which at that time were called "torpedoes", a term applied to self-propelled warheads only later, torpedo rams and a brief Confederate experiment in deploying a casemate ironclad, the CSS Arkansas, in a river defense role.