The Battle of Guam in 1944 was a pivotal military operation during World War II, in which the United States recaptured the Japanese-held island of Guam, a U.S. territory in the Mariana Islands. The battle was a critical component of Operation Forager, a larger offensive aimed at securing the Mariana Islands and gaining control of the central Pacific region. The victory at Guam not only liberated the island from Japanese occupation but also resulted in the destruction of much of Japan's naval air power. This allowed the United States to establish large airbases from which it could launch strategic bombing campaigns against the Japanese home islands using its new long-range bomber, the Boeing B-29 Superfortress.

Originally, the attack on Guam was meant to begin just days after the successful U.S. landings on Saipan, another key island in the Marianas. However, due to various logistical and tactical postponements, the invasion of Guam was delayed. U.S. forces used this additional time to their advantage, carrying out thorough preliminary naval bombardment and aerial attacks on Japanese positions. They also efficiently cleared offshore obstacles to ensure safe passage for the landing craft that would carry the invasion forces to the island's shores.

When the landings finally began on 21 July 1944, on the west coast of Guam, the U.S. invasion force consisted of 55,000 Marine and Army personnel, forming part of General Geiger's III Amphibious Corps. The island's defenders, numbering approximately 19,000 Japanese troops under the command of General Takashina, had spent considerable time and effort fortifying the island. They had built an intricate system of bunkers, artillery emplacements, and other defensive positions to repel the anticipated American assault. The main units of the III Marine Amphibious Corps tasked with the invasion included the battle-hardened 3rd Marine Division and the 1st Provisional Marine Brigade, along with the U.S. Army's 77th Infantry Division.

The 305th Regimental Combat Team (RCT) of the 77th Division landed alongside the First Provisional Marine Brigade, assaulting the southern beaches at Agat on the first day. Over the course of the next three days, the remaining elements of the division, the 306th and 307th RCTs, made their way ashore. The 77th played a crucial role in several key engagements, including the battle for the highlands above the southern beaches, the fight for the Orote Peninsula, and the clashes at Yona and Barrigada. They continued to push northward toward Yigo, where the Japanese forces made their final stand.

Led by Colonel James T. Scott, the 1st Provisional Marine Brigade was tasked with securing the southern beaches of Guam, while other units landed to the north. The brigade encountered lighter resistance than their counterparts, but that did not mean their mission was easy. Japanese forces had fortified Gaan Point, a strategic location between the two landing zones, with mountain guns and other defenses that had gone undetected in U.S. reconnaissance probes.

Despite the unexpected resistance, the Marines of the 1st Provisional Marine Brigade pressed forward with their mission. They spent most of the day capturing Gaan Point, facing fierce Japanese resistance every step of the way. The 2nd Battalion of the brigade even took Mount Alifan, a towering peak 3300 feet inland, after a grueling climb through dense jungle.

Top photo: Guam, July 1944: U.S. Marines land ashore. Guam USMC Photo No. 1-7. From the Frederick R. Findtner Collection (COLL/3890), Marine Corps Archives & Special Collections. In the United States Public Domain. Click to enlarge.

Middle photo: Marines and their doberman pincers advance. Guam USMC Photo No. 1-13. From the Frederick R. Findtner Collection (COLL/3890), Marine Corps Archives & Special Collections. In the United States Public Domain. Click to enlarge.

Bottom photo: U.S. Marines moving inland and setting up a perimeter. Note the .30 cal. machine gun to the left of the large tree. Guam USMC Photo No. 1-12. From the Frederick R. Findtner Collection (COLL/3890), Marine Corps Archives & Special Collections. United States Public Domain. Click to enlarge.

But the fight was far from over. The brigade joined forces with the 4th and 22nd Marines to cut off the Orote Peninsula and push northward. Along the way, they faced heavy resistance from the remaining Japanese defenders, who had entrenched themselves in the island's rugged terrain. The Marines fought with all their might, clearing out one fortified position after another.

Despite facing fierce resistance and a series of determined night attacks by the Japanese defenders in the first few days of the battle, the American landing forces managed to establish a strong foothold on the island. It took approximately a week for the U.S. troops to link their two separate beachheads, by which time much of the Japanese strength had been depleted, and their commander, General Takashina, had been killed in action. The surviving Japanese units continued to resist, gradually withdrawing toward the northern end of the island as they fought a series of delaying actions against the advancing Americans. Eventually, organized Japanese opposition largely subsided, although the mountainous terrain of Guam allowed a few die-hard defenders to hold out in isolated pockets of resistance.

Small groups of Japanese soldiers continued to engage in sporadic guerrilla-style attacks long after the main battle had concluded, occasionally inflicting casualties on U.S. forces. Remarkably, in 1972, nearly three decades after the end of World War II, a lone Japanese veteran emerged from the jungle to finally surrender and return to his homeland. 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, surviving on a diet of shrimp, coconuts, and edible plants. Yokoi's astonishing story of survival and adaptation in the harsh environment of Guam's jungle captured the world's attention. 

The successful recapture of Guam provided the United States with a strategically important harbor and airfields, which would prove invaluable for future operations against the Japanese Empire. Moreover, the liberation of Guam held great symbolic significance, as it meant the restoration of U.S. sovereignty over the island, which had been captured by the Japanese in the early stages of the war in 1941.

The cost of the battle was high for both sides. American casualties amounted to approximately 1,700 killed and 6,000 wounded, while Japanese losses were even more staggering, with an estimated 18,000 soldiers killed in action. The 3rd Marine Division fought a grueling 21-day battle through the dense jungles of Guam from July 21 to August 10, 1944. Despite fierce resistance, the Marines relentlessly pushed forward, capturing over 60 square miles of territory and inflicting heavy casualties on the enemy, with over 5,000 Japanese soldiers killed. The initial phase of intense combat was followed by two months of continuous mopping up operations to eliminate pockets of leftover Japanese forces. Victory came at a heavy price, with the division suffering 677 Marines killed, 3,626 wounded, and nine missing by the end of the battle. Although this was the 77th's first action during World War II, they demonstrated remarkable tenacity and performed commendably throughout the operation. The division suffered over a thousand casualties during the battle for Guam.

The Battle of Guam, along with other key engagements in the Mariana and Palau Islands, represented a decisive turning point in the Pacific campaign of World War II. These hard-fought victories enabled the United States to gain control over this strategic region, severing vital Japanese supply lines and establishing a solid foundation for the eventual defeat of Japan. The capture of the Marianas also brought the Japanese homeland within range of U.S. bombers, setting the stage for the intense aerial campaign that would ultimately lead to Japan's surrender in August 1945.

Bibliography

Toll, Ian W. The Conquering Tide: War in the Pacific Islands, 1942-1944 (Vol. 2): War in the Pacific Islands, 1942–1944. New York: W. W. Norton & Company, 2015.

 Toll, Ian W. Twilight of the Gods: War in the Western Pacific, 1944-1945 (Vol. 3) (The Pacific War Trilogy). New York: W. W. Norton & Company, 2020.

 Wheeler, Richard. A Special Valor: The U.S. Marines and the Pacific War. Annapolis: Naval Institute Press, 2006.