The Japanese military was determined to inflict a casualty rate so high that the U.S. government would give up its demand that Japan surrender unconditionally. To this end, the island had been covered with an extremely extensive system of fortifications and fields of fire. The
United States Navy subjected the island to an unprecedented bombardment and, according to historian
Samuel Eliot Morison, "In no previous operation in the Pacific had naval gunfire support been so effective as at Iwo Jima."[1] Nonetheless, Japanese artillery and machine-gun fire were extremely effective because the underground bunkers were so strong, only a direct hit by a bomb or naval shell could knock one out. Since direct hits were very difficult on well-camouflaged bunkers, many survived and inflicted a huge casualty rate on the Marines.
For the conquest of Iwo Jima, the Marine Corps assigned three divisions, a total of almost 70,000 troops, in stark contrast to the single division tasked with capturing
Guadalcanal in August 1942. The conquest of Iwo Jima took five weeks, far beyond the American estimates.
5th Marine Division command post on Iwo Jima; at left is Asst. Div. Cmdr. Leo D. Hermle with Div. Cmdr. Keller E. Rockey holding a field telephoneA Marine Corps howitzer at the moment of firingJeeps firing 4.5-inch rockets at Japanese positions
Men of the 4th Marine Division pinned down on the beach at Iwo Jima; LSM-46 is visible in the backgroundJapanese gun emplacement lightly damaged by bombardment; Marines still had to enter the enclosure and kill the troops inside.Black Marines with DUKW at Iwo Jima
5th Amphibian Tractor Battalion (Maj. George L. Shead)
10th Amphibian Tractor Battalion (Maj. Victor J. Croizat)
4th Engineer Battalion (Lt. Col. Nelson K. Brown)
4th Medical Battalion (Cmdr. Reuben L. Sharp, USN)
4th Motor Transport Battalion (Lt. Col. Ralph L. Schiesswohl)
4th Pioneer Battalion (Lt. Col. Richard G. Ruby)
4th Service Battalion (Lt. Col. John F. Fondahl)
4th Tank Battalion (Lt. Col. Richard K. Schmidt)
3rd Marine Division command
Maj. Gen. Graves B. Erskine
William A. Worton as a colonel
3rd Marine Division officers on Iwo Jima: (l. to r.) Col. Robert W. Hogaboom, Maj. Gen. Graves B. Erskine, Col. John B. WilsonMarines firing a 155mm howitzerFierce combat continued as Airfield No. 1 was scraped and graded.
Clark, George B. (2006). The Six Marine Divisions in the Pacific: Every Campaign of World War II. Jefferson, North Carolina: McFarland and Co.
ISBN978-0-7864-2769-7.
The Japanese military was determined to inflict a casualty rate so high that the U.S. government would give up its demand that Japan surrender unconditionally. To this end, the island had been covered with an extremely extensive system of fortifications and fields of fire. The
United States Navy subjected the island to an unprecedented bombardment and, according to historian
Samuel Eliot Morison, "In no previous operation in the Pacific had naval gunfire support been so effective as at Iwo Jima."[1] Nonetheless, Japanese artillery and machine-gun fire were extremely effective because the underground bunkers were so strong, only a direct hit by a bomb or naval shell could knock one out. Since direct hits were very difficult on well-camouflaged bunkers, many survived and inflicted a huge casualty rate on the Marines.
For the conquest of Iwo Jima, the Marine Corps assigned three divisions, a total of almost 70,000 troops, in stark contrast to the single division tasked with capturing
Guadalcanal in August 1942. The conquest of Iwo Jima took five weeks, far beyond the American estimates.
5th Marine Division command post on Iwo Jima; at left is Asst. Div. Cmdr. Leo D. Hermle with Div. Cmdr. Keller E. Rockey holding a field telephoneA Marine Corps howitzer at the moment of firingJeeps firing 4.5-inch rockets at Japanese positions
Men of the 4th Marine Division pinned down on the beach at Iwo Jima; LSM-46 is visible in the backgroundJapanese gun emplacement lightly damaged by bombardment; Marines still had to enter the enclosure and kill the troops inside.Black Marines with DUKW at Iwo Jima
5th Amphibian Tractor Battalion (Maj. George L. Shead)
10th Amphibian Tractor Battalion (Maj. Victor J. Croizat)
4th Engineer Battalion (Lt. Col. Nelson K. Brown)
4th Medical Battalion (Cmdr. Reuben L. Sharp, USN)
4th Motor Transport Battalion (Lt. Col. Ralph L. Schiesswohl)
4th Pioneer Battalion (Lt. Col. Richard G. Ruby)
4th Service Battalion (Lt. Col. John F. Fondahl)
4th Tank Battalion (Lt. Col. Richard K. Schmidt)
3rd Marine Division command
Maj. Gen. Graves B. Erskine
William A. Worton as a colonel
3rd Marine Division officers on Iwo Jima: (l. to r.) Col. Robert W. Hogaboom, Maj. Gen. Graves B. Erskine, Col. John B. WilsonMarines firing a 155mm howitzerFierce combat continued as Airfield No. 1 was scraped and graded.
Clark, George B. (2006). The Six Marine Divisions in the Pacific: Every Campaign of World War II. Jefferson, North Carolina: McFarland and Co.
ISBN978-0-7864-2769-7.