[b] The American ground forces were supported by extensive naval artillery and had complete air supremacy provided by U.S. Navy and Marine Corps aviators throughout the battle.

[c] Most of the remainder were killed in action, but it has been estimated that as many as 3,000 continued to resist within various cave systems on the island after most major fighting ended, until they eventually succumbed to their injuries or surrendered weeks later.

Joe Rosenthal's Associated Press photograph of the raising of the U.S. flag at the summit of the 169 m (554 ft) Mount Suribachi by six U.S. Marines became a famous image of the battle and the American war effort in the Pacific.

Iwo Jima was considered strategically important since it provided an air base for Japanese fighter planes to intercept long-range B-29 Superfortress bombers flying to strike targets in Japan.

The expected American naval and air bombardment prompted the creation of an extensive network of tunnels connecting otherwise disparate fighting positions, so that a pillbox that had been cleared could be reoccupied later.

For instance, the Nanpo Bunker (Southern Area Islands Naval Air HQ), which was east of Airfield Number 2, had enough food, water, and ammunition for the Japanese to hold out for three months.

Major General Harry Schmidt, commander of the Marine landing force, requested a 10-day heavy bombardment of the island immediately preceding his planned amphibious assault.

After the war, Lieutenant General Holland M. "Howlin' Mad" Smith, commander Expeditionary Troops (Task Force 56, which consisted of Schmidt's Fifth Amphibious Corps), bitterly complained that a frequent lack of supporting naval gunfire had cost Marine lives throughout the Allied island-hopping campaign.

The Marines initially began deployment on the beach in good order,[31] but the landings swiftly became congested due to the loose volcanic ash that covered the island.

[32] At first it came as a ragged rattle of machine-gun bullets, growing gradually lower and fiercer until at last all the pent-up fury of a hundred hurricanes seemed to be breaking upon the heads of the Americans.

First to go was the gas mask ...[31]The Japanese crews manning the heavy artillery in Mount Suribachi opened reinforced steel doors shielding their positions in order to fire, and then closed them immediately afterward to prevent counterfire from the Marines and U.S. Navy gunners.

"[35] Amtracs, unable to gain traction in the black ash, made no progress up the slopes dominating the beach; their Marine passengers had to dismount and slog forward on foot.

This allowed the Marines to finally make some progress inland and get off the beach, which had become overcrowded with both men and materiel as follow-on waves of landing craft continued to unload.

2nd Lieutenant Benjamin Roselle, part of a ground team directing naval gunfire, described the following experience: Within a minute a mortar shell exploded among the group ... his left foot and ankle hung from his leg, held on by a ribbon of flesh ...

At night, the Japanese left their defenses in small groups to attack American foxholes under cover of darkness, and U.S. Navy ships began firing star shells to illuminate the battlefield.

[12] The flag raising picture was later used by Felix de Weldon to sculpt the Marine Corps War Memorial which is located adjacent to Arlington National Cemetery since 1954.

[12] Three of the six Marines depicted in the photograph, Sergeant Michael Strank, Corporal Harlon Block, and Private First Class Franklin Sousley, were killed in action days after the flag-raising.

The patrol commander, First Lieutenant Harold Schrier, was handed the battalion's American flag to be raised on top to signal Suribachi's capture, if they reached the summit.

[46] American troops observed that during bombardments, the Japanese would hide their guns and themselves in caves, only to reemerge when Marine units began to advance and lay down devastating fire on them.

[citation needed] Additionally, this would also be a departure from the normal practice of commanding Japanese officers committing seppuku behind the lines while their subordinates perished in a last-ditch banzai charge, as occurred during the battles of Saipan and Okinawa.

[citation needed] Once the island was officially declared secure, the U.S. Army's 147th Infantry Regiment was ostensibly there to act as a garrison force, but soon found itself locked in a bitter struggle against thousands of Japanese holdouts engaging in a guerrilla campaign to harass the Americans.

Flamethrower operators were usually in more danger than regular troops as the short range of their weapon required close combat, and the visibility of the flames on the battlefield made them a prominent target for snipers.

At Schofield Barracks in Hawaii, Colonel Unmacht's top secret "Flame Thrower Group" located eight M4A3 Sherman medium tanks to convert for Operation Detachment.

"[61] By comparison, the much larger scale 82-day Battle of Okinawa lasting from early April until mid-June 1945 (involving five U.S. Army and two Marine Corps divisions) resulted in over 62,000 U.S. casualties, of whom over 12,000 were killed or missing.

[65][failed verification] In hindsight, given the number of casualties, the necessity and long-term significance of the island's capture to the outcome of the war became a contentious issue and remains disputed.

"[10] The lessons learned on Iwo Jima served as guidelines for the Battle of Okinawa in April 1945, and influenced American planning for an invasion of the Japanese Home Islands.

[69] The justification behind Iwo Jima's strategic importance to the United States' war effort revolves around the island's role as a landing and refueling site for long-range fighter escorts.

[71] Japanese fighter aircraft based on Iwo Jima occasionally attacked U.S. Army Air Force bombers, which were vulnerable en route to Japan because they were heavily laden with bombs and fuel.

The sight of the enormous, costly, and technologically sophisticated B-29 landing on the island's small airfield most clearly linked Iwo Jima to the strategic bombing campaign.

Other notable attendees included then Brigadier General William K. Jones commander of the 3rd Marine Division and NBC’s senior correspondent in Asia John Rich.