 The Neosho @-@ class monitors were a pair of ironclad river monitors laid down in the summer of 1862 . After completion in mid @-@ 1863 , both ships spent time patrolling the Mississippi River against Confederate raids and ambushes as part of Rear Admiral David Porter 's Mississippi Squadron . Both ships participated in the Red River Campaign in March – May 1864 .
 kwietnia 1864 , the Neosho was attacked by Confederate raiders in the Red River . The Neosho was the first ironclad to be sunk by an enemy torpedo .
The Neosho was the first ironclad to be sunk by an enemy