Grenada World War II Roosevelt Hoisting the flag over Iwo Jima 1970

The truly groundbreaking invention of the Confederacy was the CSS HL Hunley, the world's first operational submarine to sink an enemy ship in battle. The Confederate submarine is depicted on the 50-cent Grenada-Grenadines stamp (Scott 880), issued in 1987 as part of a series dedicated to transportation innovation.
On the night of 17 February 1864, the CSS HL Hunley, using the torpedo Spar, attacked and sank the USS Housatonic. Unfortunately, the submarine also sank after the attack, losing its entire crew of seven. Two other crews had previously died in accidents during exercises.