Invasion Of Guam

The Battle of Guam (21 July – 10 August 1944) was the American recapture of the Japanese-held island of Guam, a U.S. territory in the Mariana Islands captured by the Japanese from the United States in the First Battle of Guam in 1941 during the Pacific campaign of World War II. The battle was a critical component of Operation Forager. The recapture of Guam and the broader Mariana and Palau Islands campaign resulted in the destruction of much of Japan's naval air power and allowed the United States to establish large airbases from which it could bomb the Japanese home islands with its new strategic bomber, the Boeing B-29 Superfortress.

The invasion of Saipan was scheduled for 15 June 1944, with landings on Guam tentatively set for just three days later, but the Battle of the Philippine Sea and stubborn resistance by the unexpectedly large Japanese garrison on Saipan led to the invasion of Guam being postponed for over a month. On 21 July, American forces landed on both sides of the Orote Peninsula on the western side of Guam, planning to secure Apra Harbor. The 3rd Marine Division landed at Asan near Agana to the north of Orote, and the 1st Provisional Marine Brigade landed near Agat to the south. The men stationed in the two beachheads were pinned down by heavy Japanese fire, making initial progress inland quite slow. Supply was very difficult; landing ships could not come closer than the reef, several hundred yards from the beach, and amphibious vehicles were scarce.

The 1st Provisional Brigade blocked off the Orote Peninsula on 25 July, and that night the Japanesecounterattacked, in coordination with an attack against the 3rd Marine Division to the north. The effort was a failure. On 28 July the two beachheads were linked, and by 29 July the Americans had secured the Orote peninsula. The Japanese counterattacks against the American beachheads and the fierce fighting beforehand had exhausted them. By the start of August, they were running out of food and ammunition, and they had only a handful of tanks left. They withdrew from southern Guam, planning to make a stand in the mountainous central and northern part of the island, and to engage in a delaying action.

Rain and thick jungle made conditions difficult for the Americans, but after an engagement with the main Japanese line of defense around Mount Barrigada from 2 to 4 August, the Japanese line collapsed. On 10 August organized Japanese resistance ended, and Guam was declared secure, but 7,500 Japanese soldiers were estimated to be at large.

Background

Geography

Guam, at , is the largest of the Mariana Islands, larger than the other fourteen major islands combined. It is long from north to south, with a width ranging from at different points of the island. Along with the other Mariana Islands, Guam was claimed for Spain by Miguel López de Legazpi on 26 January 1565. It became a United States possession after its capture from Spain in June 1898, during the Spanish-American War. Two months later, Spain ceded Guam and the Philippines to the United States for $20 million (equivalent to $ million in ), and the island became an unincorporated territory. The island was captured by the Japanese on 10 December 1941, following the attack on Pearl Harbor that brought the United States into World War II.

The island is surrounded by coral reefs varying from wide. The northern coastline is fringed with cliffs. Beyond is a limestone plateau, broken up by three hills, Mounts Barrigada, Santa Rosa and Machanao. The southern part of the island is also fringed with reefs and cliffs, but there are breaks in the reefs and the cliffs are lower. The highest peak was Mount Lamlam near the south west coast. Running north of it are Mount Alifan, Tenjo, Chachao and Aluyom. The best beaches lie in between, around Apra Harbor and Agat Bay. Before the war, the harbor was used by United States Navy and PanAm seaplanes; there were no airfields before the Japanese occupation. The Japanese built a airfield on the Orote Peninsula, and a east of the capital, Agana, was nearing completion in July 1944. The average temperature was about and humidity was 90 percent, with daily rainfall between July and December. In these months, the unpaved roads became all but impassable.

The population of Guam in 1941 was about 23,400, of whom 21,500 were Chamorro people, the indigenous people of the Mariana Islands, who were United States nationals, but not citizens. The garrison consisted of 400 United States Marine Corps and Navy personnel. Most of the population, about 12,500 people, lived in Agana. The Chamorro population suffered considerably during the Japanese occupation of Guam. When it became clear that the island would soon be invaded, Japanese soldiers committed numerous atrocities. The Japanese forcibly relocated most of the island's population to concentration camps in eastern and southern Guam, most notably Manenggon. The camps were without food, shelter or sanitation. It saved them from the American bombardment of the island, although that was not the intent. The catholic priest and local leader Jesus Baza Dueñas was tortured by Japanese interrogators seeking information on George Tweed, and American who had evaded captured when the island was occupied. Dueñas, his nephew Eduardo, and two other men were beheaded on 12 July. They died without knowing that Tweed had been rescued by the destroyer two days before.

Strategy

After World War I, the United States had developed a series of contingency plans for the event of a war with Japan known as the Orange plans. These envisaged an advance through the Marshall and Caroline Islands to the Philippines, from whence Japan could be blockaded. The Mariana Islands figured only incidentally in the plans, as they lay north of the direct route between Hawaii and the Philippines. During World War II, the islands attracted the attention of naval and air strategists. At the Casablanca Conference in January 1943, the US and British Combined Chiefs of Staff endorsed a Central Pacific offensive along the lines envisaged in the Orange plans. In his formulation of a Pacific strategy, the Commander in Chief, United States Fleet, Admiral Ernest J. King, specifically mentioned the Mariana Islands as "the key to the situation because of their location on the Japanese line of communication."

King envisaged the Marianas primarily as a naval base, especially for submarines, but another rationale for their capture emerged with the development of the long-range Boeing B-29 Superfortress bomber. From the Mariana Islands, B-29s could reach the most significant industrial targets in Japan, and the air staff planners began incorporating the islands into their long-range plans in September 1943. The Commander in Chief, Pacific Ocean Areas (CINCPOA), Admiral Chester W. Nimitz, produced a campaign plan called Operation Granite, which tentatively scheduled the capture of Mariana Islands of Saipan, Tinian and Guam for 15 November 1944.

By February 1944, there was consideration of advancing the timetable by bypassing Truk and heading directly for Palau or the Marianas after the capture of the Marshall Islands. On 7 March, Nimitz and his Deputy Chief of Staff, Rear Admiral Forrest P. Sherman met with the Joint Chiefs of Staff in Washington, D.C., where they were questioned by the Chief of Staff of the United States Army, General George C. Marshall, and the Chief of Staff to the Commander in Chief, Admiral William D. Leahy. Sherman argued that the neutralization of Truk required the occupation of the Mariana Islands to cut the air route to Truk from Japan. On 12 March, the Joint Chiefs directed Nimitz to neutralize Truk and occupy the Mariana Islands, with a target date of 15 June 1944.

Although Saipan and Tinian were more suitable as long-range bomber bases, since they were closer to Japan, Guam was the most desirable of the Mariana Islands for a naval base, because it had a more adequate water supply and the best anchorage in Apra Harbor. It was decided to invade Saipan first, though, because aircraft based their could then protect Tinian and Guam from air attacks from Japan staging through the Nanpō Islands. The operation to capture the Marianas was codenamed Operation Forager; Guam was codenamed "Stevedore".

Opposing forces

United States

Overall command of the operation would be exercised by Nimitz through the commander of the Fifth Fleet, Admiral Raymond A. Spruance. Under Spruance was the commander of the Joint Expeditionary Force (Task Force 51), Vice Admiral Richmond K. Turner and the commander of the Expeditionary Troops (Task Force 56), Lieutenant General Holland M. Smith. Task Force 51 was divided into the Northern Attack Force (Task Force 52), under Turner, which would land and support the troops on Saipan and Tinian, and the Southern Attack Force (Task Force 53), under Rear Admiral Richard L. Conolly, the commander of Amphibious Group 3, which would land and support the troops on Guam. In addition to the two defense battalions, Brigadier General Pedro Augusto del Valle's III Amphibious Corps Artillery had the 1st and 2nd 155 mm Howitzer Battalions and the 7th 155 mm Gun Battalion. A Marine Corps observation squadron, VMO-1, was also assigned.

In Nimitz's preliminary order of 20 March 1944, the task was recapturing Guam was assigned to Major General Roy S. Geiger's I Marine Amphibious Corps, which was renamed the III Amphibious Corps on 15 April. For this operation, Geiger had the 3rd Marine Division, the 1st Provisional Marine Brigade and the 9th and 14th Defense Battalions. The 3rd Marine Division was commanded by Major General Allen H. Turnage. The 1st Provisional Marine Brigade was activated at Pearl Harbor on 22 March and Brigadier General Lemuel C. Shepherd Jr. assumed command on 16 April. The brigade was built around the 4th Marine Regiment on Emirau and the 22nd Marine Regiment, which was in the Marshall Islands; both were ordered to move to Guadalcanal. The 27th Infantry Division was designated the reserve for both the Northern and Southern Attack Forces. The Pacific Ocean Areas reserve was the 77th Infantry Division, which was still in the United States, but under orders to move to Hawaii.

Geiger's headquarters was on Guadalcanal in the Solomon Islands, so, on 29 March, he flew to Pearl Harbor with members of his staff to confer with Spruance, Turner, Smith and Conolly. The plan they drew up, Operation Plan (OpPlan) 1-44, was approved by Smith on 3 April and Turner and Spruance the following day. It called for simultaneous landings on either side of the Orote Peninsula, with a northern attack group under Conolly's command landing the 3rd Marine Division between Adelup Point and the Tatgua River, while a south attack group under Rear Admiral Lawrence F. Reifsnider landed the 1st Provisional Marine Brigade on the beaches between Agat and Bangi Point. The vital Orote Penisula and Apra Habor area would be seized by a double envelopment. That the area was likely to be heavily defended was not overlooked, but in the Battle of Munda Point the tactic of landing elsewhere and fighting through the jungle to the objective had proved to be both slow and costly. Geiger returned to Guadalcanal on 7 April, and Conolly joined him there eight days later, co-locating his headquarters with Geiger's until the command ship arrived from Pearl Harbor on 27 April.

In addition to the main plan, two alternative plans were developed to cover the contingencies where one of the beaches was found to be too heavily defended or otherwise unsuitable. OpPlan 3-44 provided for landing the entire force in the south between Agat and Facpi Point, while OpPlan 4-44 provided for the 1st Provisional Marine Brigade to land further south, between Bangi and Facpi Points. The landing date, codenamed W-Day to avoid confusion with Saipan's D-Day, was tentatively set for 18 June, three days after the landing on Saipan.

Japanese

For most of the period of Japanese occupation, the garrison on Guam consisted was the 150 sailors of the 54th . In September 1943, indications of an impending American assault on the Gilbert Islands led to a reconsideration of the defense of the island. The 13th Division, which had been serving in China since 1937, was ordered to Guam. An advance party of 300 men sailed for Guam in October 1943, but the main body of the division never followed, as it was diverted to participate in Operation Ichi-Go in southern China.

In February 1944, the 29th Division in Manchuria, under the command of Lieutenant General Takeshi Takashina, was ordered to the Marianas. It embarked from Korea in three ships on 24 February. En route, the ''Sakito Maru'', carrying 4,124 troops, including the division's 18th Infantry Regiment, was torpedoed and sunk by an American submarine, the on 29 February. The destroyers escorting the convoy depth charged ''Trout'', which went down with all hands, and took the 1,620 survivors to Saipan. The 1st Battalion remained there; the rest of the regiment, under the command of Colonel Hiko-Shiro Ohashi, continued on to Guam, eventually arriving there on 4 June. The division's 50th Infantry Regiment went to Tinian, while rest of the division, including Colonel Tsunetara Suenaga's 38th Infantry Regiment, reached Guam on 4 March.

The forces on Guam were further reinforced by the 6th Expeditionary force, which embarked from Pusan with 4,700 men from the Kwantung Army's 1st and 11th Divisions. It arrived on Guam on 20 March, where the three battalions of the 11th Division became four battalions (numbered 319th to 322nd) of the 48th Independent Mixed Brigade, under the command of Major General Kiyoshi Shigematsu, and those of 1st Division became the 10th Independent Mixed Regiment, under the command of Colonel Ichiro Kataoka. In June, the 1st Battalion, 10th Mixed Regiment, were sent to Rota. The 3rd Battalion, 38th Infantry Regiment, was also sent there, to make a counter-landing on Saipan, but sea conditions rendered this impossible, and it returned to Guam on 29 June.

The 54th was steadily reinforced with coast defence and anti-aircraft units until it reached a strength of about 2,300 in July 1944. It was under Captain Yutaka Sugimoto, the former island commander. In addition, there were two naval construction battalions (), the 217th and 218th, totaling 1,080 men, that had been sent to work on the airfields, but were available for employment in combat. In total, there was about 5,000 naval ground troops and 2,000 men in naval air units. The total Japanese strength on Guam on 18 July was about 18,500 men. Takashina was in command, although his superior, Lieutenant General Hideyoshi Obata, the commander of the Thirty-First Army, who had overall responsibility for the defense of the Mariana Islands, was also on Guam, having been waylaid while returning from Palau to to his headquarters on Saipan when the Americans invaded that island.

Preliminary operations

U.S. naval and air bombardments were carried out from 11 to 13 June 1944, involving 216 carrier aircraft and land-based B-24 bombers from the Marshall Islands. On 12 and 13 June twelve Japanese cargo ships and several fishing vessels were sunk. On 27 June, U.S. Navy battleships and cruisers started shelling the island, joined by a carrier group on 4 July, and two more on 6 July.

The original timetable was optimistic, however. A large Japanese carrier attack and stubborn resistance by the unexpectedly large Japanese garrison on Saipan led to the invasion of Guam being postponed for a month.
274 ships fired 44,978 rounds from 2- and 5-inch guns in support of the landing. In addition, 13 aircraft carriers participated in the air raid, and 4,283 bombs (weighing 1,310 tons) were dropped from 18 to 20 July, the day before the landings. The heavy bombardment burned all the palm trees on the beach and destroyed every building that could be seen.
Experience gained by the Japanese from the invasion of Saipan was used to try to mitigate the effects of the bombardment. Despite this, the bombardment far exceeded the expectations of the defending forces, which were dug in along the coast as they were on Saipan. Many of the bases and guard towers were destroyed. However, artillery pieces entrenched in dense forests, caves, trenches and locations four kilometers or more from the coast were able to escape destruction and became a source of heavy Japanese resistance. Guam, ringed by reefs, cliffs, and heavy surf, presents a formidable challenge for any attacker. Underwater Demolition Teams reconnoitered the beaches and removed obstacles from 14 to 17 July.

Battle

Despite the obstacles, on 21 July the American forces landed on both sides of the Orote Peninsula on the western side of Guam, planning to secure Apra Harbor. The 3rd Marine Division landed at Asan near Agana to the north of Orote at 08:29, and the 1st Provisional Marine Brigade landed near Agat to the south. Japanese artillery sank 30 U.S. LVTs and inflicted heavy casualties on the landing troops, especially of the 1st Provisional Marine Brigade, but by 09:00 Marines and tanks were ashore at both beaches.

By nightfall, the Marines and soldiers of the 77th Infantry Division had established beachheads about deep. The 77th Infantry Division had a more difficult landing on 23–24 July. Lacking amphibious vehicles, they had to wade ashore from the edge of the reef where the landing craft dropped them off. The men stationed in the two beachheads were pinned down by heavy Japanese fire, making initial progress inland quite slow. Supply was very difficult for the landing troops on Guam in the first days of the battle; landing ships could not come closer than the reef, several hundred yards from the beach, and amphibious vehicles were scarce.

The 1st Provisional Brigade blocked off the Orote Peninsula on 25 July, and that same night Takashina counterattacked, coordinated with a similar attack against the 3rd Division to the north. The next day, Obata reported, "our forces failed to achieve the desired objectives." Takashina was killed on 28 July, and Obata took over command. On 28 July the two beachheads were linked, and by 29 July the Americans had secured the peninsula.

The Japanese counterattacks against the American beachheads, as well as the fierce fighting, had exhausted the Japanese. At the start of August, they were running out of food and ammunition, and they had only a handful of tanks left. Obata withdrew his troops from southern Guam, planning to make a stand in the mountainous central and northern part of the island, "to engage in delaying action in the jungle in northern Guam to hold the island as long as possible".

After ensuring that no significant Japanese forces operated in the southern portion of Guam, Marine Major General Roy S. Geiger started an offensive north with the 3rd Marine Division on the left flank and the 77th Infantry Division on the right, liberating Agana on the same day. The Tiyan Airfield was captured on 1 August.

Rain and thick jungle made conditions difficult for the Americans, but after an engagement with the main Japanese line of defense around Mount Barrigada from 2 to 4 August, the Japanese line collapsed. The 1st Provisional Brigade formed up on the left flank of the 3rd Marine Division on 7 August because of the widening front and continued casualties, in an effort to prevent the Japanese from slipping through gaps in the line. The Japanese had another stronghold at Mount Santa Rosa, which was secured by US forces on 8 August.

On 10 August organized Japanese resistance ended, and Guam was declared secure, but 7,500 Japanese soldiers were estimated to be at large. The next day, Obata committed ritual suicide at his headquarters on Mount Mataguac after he had sent a farewell message to Japan.

Aftermath

A few Japanese soldiers held out in the jungle for years after the fighting on Guam. On 8 December 1945, three U.S. Marines were ambushed and killed. Sergeant Masashi Itō surrendered on 23 May 1960, after the last of his companions was captured. On 24 January 1972, Sergeant Shoichi Yokoi was discovered by hunters on the island. He had lived alone in a cave for 28 years, near Talofofo Falls.

Guam was turned into a base for Allied operations after the battle. Five large airfields were built by the Navy Seabees and African American Aviation Engineering Battalions. Army Air Forces B-29 bombers flew from Northwest Field and North Field on Guam to attack targets in the Western Pacific and on mainland Japan.

Liberation Day continues to be celebrated on Guam on the anniversary of the US landing, every 21 July.

Unit awards

Navy Unit Commendation:
* 1st Provisional Marine Brigade, 21 July to 10 August 1944

Medal of Honor recipients

Four Medal of Honor recipients of the Battle of Guam:
* Captain Louis H. Wilson Jr., USMC
* Private First Class Leonard F. Mason, USMC (posthumous)
* Private First Class Luther Skaggs Jr., USMC
* Private First Class Frank P. Witek, USMC (posthumous)

See also

* Agana race riot – Violent confrontation between white U.S. Marines and black U.S. sailors
* '' Return to Guam'', 1944 documentary and propaganda film about the battle
* The War in the Pacific National Historical Park

Notes

References

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Further reading

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External links

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"The Marianas and the Great Turkey Shoot"
World War II Database.
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''Photos from the Liberation of Guam''
The Real Revo
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{{DEFAULTSORT:Guam
Mariana and Palau Islands campaign
Conflicts in 1944
Guam, 1944
Battle, 1944
Battle, 1944
World War II operations and battles of the Pacific theatre
Guam (1941)
Guam (1941)
Guam 1944
Amphibious operations of World War II
July 1944 in Oceania
August 1944 in Oceania
Amphibious operations involving the United States
Military in Guam