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Battle of Guam: 21 July - 10 August 1944

As the V Amphibious Corps secured Saipan and prepared to land on Tinian, the III Amphibious Corps, under the command of Marine Lieutenant General Roy Geiger, prepared for Phase III of OPERATION FORAGER: recapturing Guam, the largest and southernmost island in the Mariana chain. However, unlike previous operations this one had a personal, as well as military, impetus.

77th Infantry Division

77th Infantry Division

Battle of Guam, July 1944

After World War I, when the League of Nations granted control of the Mariana Islands to Japan, Guam had remained a protectorate of the United States. It served as a refueling station and had a small Navy Yard and Hospital and Marine Barracks manned by 153 Marines and 274 sailors and augmented by the Guamanian Insular Defense Force. On 8 December 1941, just hours after the Pearl Harbor Attack, Japanese aircraft began bombing the island, sinking the minesweeper USS Penguin. The attack was not wholly unexpected as tensions between the United States and Japan escalated and the military governor, Navy Captain George McMillin, had ordered the destruction of all classified materials on 6 December. In the early hours of 10 December, almost 6,000 Japanese troops landed. Badly outnumbered and without enough weapons to go around, after a short resistance, Captain McMillin surrendered the garrison.

Now it was time to retake the island. To accomplish this LTG Geiger had the 3rd Marine Division, the 1st Provisional Marine Brigade and the 77th Infantry Division, under the command of Major General Andrew Bruce. The attack was supposed to commence on 18 June 1944, but the harder than expected fight on Saipan forced a delay. The new invasion date was set for 21 July.

By this time the Japanese garrison had grown to more than 18,000. Although they had constructed new airfields, attrition and diversion had destroyed most of their land-based air power and, after the Battle of the Philippine Sea (the "Great Marianas Turkey Shoot") on 19-20 June, the Japanese navy had no carriers to support the island. The defenders would only have the terrain and their defenses to stop the Americans.

Despite the size of the island, due coral reefs, treacherous tides and beachside cliffs, there were relatively few suitable landing beaches. The final plan called for a two pronged attack on the western shore on each side of the Orote peninsula and Apra Bay. The 3rd Marine Division would land to the north, near the city of Agana, while the 1st Marine Provisional Brigade landed to the south, near the town of Agat. The two forces would meet around the back of the peninsula, thus cutting off the bay before clearing the rest of the island. The 305th Regimental Combat Team, 77th Infantry Division was in direct support of the Marine brigade, ready to land on command, with the rest of the division in reserve.

For sixteen days before the landing, the naval gunfire and air strikes pounded the island. Despite enemy resistance, the Marines had tanks operating ashore and quickly pressed forward. The 305th RCT received orders to land that afternoon. A lack of amphibious landing vehicles forced the many of soldiers to wade, and at times swim, through the surf. Fortunately, the Japanese were fully occupied with the Marines ashore and the soldiers took little fire. It was early in the morning of 22 July when the last of the regiment made it ashore. The rest of the division began to land on 23 July.

By 29 July the two landing forces had linked up and secured the peninsula. The Japanese forces had concentrated in the in mountainous area in the in the center and northern part of the island, so the Americans turned north. With the 3rd Marine Division on the left and the 77th Infantry Division on the right, they moved slowly up the island. They defeated the last Japanese stronghold at Mount Santa Rosa on 8 August. General Geiger declared the island secure on 10 August.

CMH Related Publications

  • The War Against Japan
  • Western Pacific by Charles R. Anderson
  • Campaign in the Marianas, by Philip A. Crowl