The American invasion of the island of Okinawa, codenamed Operation Iceberg, took place 1 April 1945. The Japanese military was determined to inflict a casualty rate so high that the U.S. government would choose not to invade the Japanese home islands. To this end, the southern portion of the island had been covered with the most extensive system of fortifications and fields of fire yet encountered in the Pacific War.
The island was not declared secure until 22 June, a period of 82 days. Lieutenant General Simon Bolivar Buckner Jr., was struck by coral fragments created by the explosion of a Japanese artillery shell on 18 June and later died of his wounds. Buckner became the highest ranking U.S. military officer to be killed in action in the Second World War.
US Tenth Army
Lieutenant General Simon Bolivar Buckner Jr., USA (KIA 18 Jun)
Major General Roy S. Geiger, USMC (18 Jun thru 23 Jun)
General Joseph W. Stilwell, USA (from 23 Jun)
III Amphibious Corps (Embarked in Task Force 53)
Major General Roy S. Geiger, USMC
Chief of Staff: Brigadier General Merwin H. Silverthorn, USMC
Chief of Corps Artillery: Brigadier General David R. Nimmer, USMC
Left Beaches:
6th Marine Division (24,356 officers and enlisted)
Division Commander: Major General Lemuel C. Shepherd, Jr., USMC
Asst. Division Commander: Brigadier General William T. Clement, USMC
22nd Marine Regiment (Colonel Merlin F. Schneider, USMC) – Green Beaches
4th Marine Regiment (Colonel Alan Shapley, USMC) – Red Beaches
29th Marine Regiment (Colonel Victor Bleasdale, USMC) – Reserve
15th Marine Regiment (Artillery) (Colonel Robert B. Luckey, USMC)
Right Beaches:
1st Marine Division (26,274 officers and enlisted)
Division Commander: Major General Pedro A. del Valle, USMC
Asst. Division Commander: Brigadier General Louis R. Jones, USMC
7th Marine Regiment (Colonel Edward W. Snedeker, USMC) – Blue Beaches
5th Marine Regiment (Colonel John H. Griebel, USMC) – Yellow Beaches
1st Marine Regiment (Colonel Arthur T. Mason, USMC) – Reserve
11th Marine Regiment (Artillery) (Colonel Wilburt S. Brown, USMC)
1st Provisional Antiaircraft Artillery Group
Commanding officer: Colonel Kenneth W. Benner, USMC
XXIV Army Corps (Embarked in Task Force 55)
Major General John R. Hodge, USA
Left Beaches:
7th Infantry ("Bayonet") Division (21,929 officers and enlisted)
Division Commander: Major General Archibald V. Arnold, USA
17th Infantry Regiment – Purple Beaches
32nd Infantry Regiment – Orange Beaches
184th Infantry Regiment – Reserve
48th, 49th, 57th Field Artillery Battalions (105mm)
31st Field Artillery Battalion (155mm)
Right Beaches:
96th Infantry ("Deadeye") Division (22,330 officers and enlisted)
Division Commander: Major General James L. Bradley, USA
381st Infantry Regiment – White Beaches
383rd Infantry Regiment – Brown Beaches
382nd Infantry Regiment – Reserve
361st, 362nd, 921st Field Artillery Battalions (105mm)
363rd Field Artillery Battalion (155mm)
Reserve:
27th Infantry ("New York") Division (16,143 officers and enlisted)
Division Commander: Major General George W. Griner, Jr., USA
105th Infantry Regiment – landed L+8
106th Infantry Regiment – landed L+8
165th Infantry Regiment – landed L+8
104th, 105th, 249th Field Artillery Battalions (105mm)
106th Field Artillery Battalion (155mm)
Embarked in Task Group 51.1
77th Infantry ("Statue of Liberty") Division (20,981 officers and enlisted)
Division Commander: Major General Andrew D. Bruce, USA
306th Infantry Regiment – landed Green Beach 17 Apr
305th Infantry Regiment – landed Red Beaches 1 & 2 17 Apr
307th Infantry Regiment – landed Red Beaches 3 & 4 17 Apr
304th, 305th, 902nd Field Artillery Battalions (105mm)
306th Field Artillery Battalion (155mm)
One Marine BLT
Tactical Air Force, Tenth Army
Major General Francis P. Mulcahy, USMC
Major General Louis E. Woods, USMC
Lieutenant General Mitsuru Ushijima (seppuku 22 June)
Approx. 67,000 men under arms, incl. 5,000 Okinawan conscripts[5]
Lt. Gen. Tatsumi Amamiya (KIA 30 June)
22nd Infantry Regiment
32nd Infantry Regiment
89th Infantry Regiment
Lt. Gen. Takeo Fujioka (suicide 22 June)
63rd Brigade
67th Brigade
44th Independent Mixed Brigade
Maj. Gen. Suzuki Shigeji (died 22 June)