Battle of Iwo Jima

Operation Detachment began on 19 February 1945, when U.S. Marines landed on Iwo Jima’s southern beaches. The assault force included the 4th and 5th Marine Divisions under V Amphibious Corps; the 3rd Marine Division was the reserve. Its 21st Marines landed on 21 February, and the division took over the centre of the line on 25 February; only its 3rd Marines stayed afloat and never landed. Japanese artillery and mortars opened fire after the beach had filled with landing waves, causing heavy losses and slowing movement across the volcanic sand. The defenders had built bunkers and gun positions into an extensive tunnel network, and the preliminary bombardment had not neutralized many of them.

The Marines advanced along the island’s narrow axis while fighting strongpoints and fire from Mount Suribachi. A U.S. patrol reached the summit on 23 February and raised a flag; a second flag was raised later that day. The capture of Suribachi secured the island’s southern end, but the advance north remained slow. The Japanese garrison, commanded by Lieutenant General Tadamichi Kuribayashi, had concentrated its defenses in mutually supporting positions rather than relying on a decisive counterattack at the beaches.

After Suribachi fell, the principal fighting shifted toward the airfields and fortified ground in the island’s center and north. The Marines faced repeated close assaults against caves, bunkers, and positions linked by tunnels. They used artillery, tanks, flamethrowers, and demolition charges to reduce defenses, then continued forward through difficult terrain. The fighting around named strongpoints, including “The Meat Grinder,” exacted further losses. The U.S. advance remained incremental as Japanese defenders held concealed positions and continued to resist after neighboring defenses had been overcome.

In the final phase, U.S. forces pressed into the northern part of the island and reduced remaining organized resistance. The main battle ended on 26 March, though some Japanese continued to resist in caves after the island had been declared secured. The United States won the battle, but its ground forces suffered 6,821 killed and 19,217 wounded. Japanese losses were reported as 17,845–18,375 killed or missing, with 216 prisoners taken during the main battle. The island’s civilians had been evacuated before the assault.

The map phases show the broad movement from the southern landing beaches toward the northern end of Iwo Jima. Their front lines follow the U.S. Marine Corps monograph's maps of the attack; unit symbols mark each division's sector, not a single position. The sources identified the 4th and 5th Marine Divisions and the Japanese 109th Division among the forces involved; the 3rd Marine Division is shown from 25 February, when it took over the centre.