Battle of Guam (1944)

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.