Since the battle of Iwo Jima in World War II, the United States Navy has commissioned two vessels bearing this name, both aviation-capable amphibious assault ships.
The first ship to bear the name was LPH-2 (LPH = Landing Platform, Helicopter), commissioned in 1961. The Iwo Jima was the lead ship in the class (LPH-1 being a coverted Essex-class CVA), and the first ship designed and built as a helicopter carrier. At 610 feet long and 22,500 tons displacement, she was far smaller than the Forrestal-class and Kitty Hawk-class fixed wing carriers that were her contemporaries. Her mission was to deliver troops to the beaches by using helicopters. Over her 32-year service life, she carried the UH-1 Iroquois, CH-46 Sea Knight, CH-53D Super Stallion, MH-53E Sea Dragon, AH-1 Cobra, SH-3 Sea King and SH-60 Seahawk.
The Iwo Jima was armed with 3 Mk. 15 Phalanx 20mm close-in defense guns and 4 12.7mm machine guns.
In 1970, SH-3 Sea Kings of the HS-4 squadron from the Iwo Jima retrieved the astronauts of the ill-fated Apollo 13 mission. She was also the first amphibious assault ship on station during the 1991 Gulf War. In 1993, LPH-2 was decommissioned.
In 2001, the Navy commissioned the second vessel to bear the name. This new vessel, LHD-7, is superior in all respects to her predecessor. At 844 feet long, and displacing 44,500 tons, the new Iwo Jima is significantly larger than her predecessor as well. This increased size is used to provide space for a well deck which can accomodate 3 air-cushion landing craft (LCACs). Above this level, she has a carrier-like hangar and flight deck which handles a mix of AV-8B Harrier II attack jets, CH-46 Sea Knight transport helicopters, CH-53D Super Stallion heavy lift helos, AH-1W Super Cobra attack helos, UH-1N medivac and scouting helos, MV-22 Osprey tiltrotor cargo planes, SH-60B Seahawk antisubmarine and antisurface helos and MH-60S Knighthawk SAR and VERTREP helicopters. In the near future, the F/A-35B Joint Strike Fighter, VSTOL variant, is intended to augment, then replace the AV-8s.
LHD-7 is armed with 2 Mk. 15 Phalanx CIWS, 2 22-cell launchers for Rolling airframe missiles and 2 8-cell launchers for RIM-7P Sea Sparrow missiles, which are due to be upgraded to the ESSM in the near future. Also, her aircraft are capable of launching AIM-120 AMRAAM, FIM-92 Stinger, AIM-9M and AIM-9X Sidewinder missiles, AGM-84D Harpoon anti-surface missiles, AGM-65 Maverick antitank/antiship missiles, AGM-119 Penguin anti-ship missiles and AGM-114 Hellfire antitank/antiboat missiles, plus various rockets (Hydra, Zuni), torpedoes and bombs. The F/A-35 will add the capability to employ the JSOW and AIM-135 ASRAAM.
In 2003, the Iwo Jima deployed to the coast of Liberia to perform non-combatant evacuation operations and to provide the capability to land Marines and conduct airstrikes should it have become necessary. This was her first major operational action.
Sources: chinfo.navy.mil, lhd7.navy.mil and the experiences and input of various shipmates who have served on one or both vessels bearing the name Iwo Jima.