Key Point: The Imperial Japanese had dug in hard and were not going to give it up easily. The fighting would last for a good while, but ultimately the Marines and Coast Guard would prevail.
Above all, the island was defendable. From Ritidian Point in the north to the extreme southern coastline, Guam is 34 miles long, made in an irregular shape covering 228 square miles, the largest of all Pacific islands between Japan and New Guinea. It is surrounded by coral reefs, and the island’s mountains rise more than 500 feet.
Prewar Guam had only a few miles of asphalt roads. As soon as the rainy season began in July, the dirt roads would turn to mud. July was also typhoon season, and tides would be unusually high. In July 1944 Guam was the next target for invasion. The Marianas island chain was critical to the American advance against Japan. In American hands, the islands would become major air and naval bases. Guam was also prewar American territory. Won from Spain in the 1898 war and confirmed by treaty in 1901, the island’s 22,290 residents (1940 Census), while not American citizens, lived under the protection of the American flag.
Japanese Occupiers of Guam
After Japan conquered the island on December 10, 1941, the islanders groaned under enemy rule. The Japanese confiscated land and reduced the island’s farmers to the level of slaves working in the rice fields. As the war droned on, the Guamanians were impressed to build defenses against American attack.
The Japanese planned to move the veteran 13th Infantry Division from China to the Marianas, but only sent 300 men in an advance detachment. They then assigned the 29th Infantry Division, part of the Kwantung Army in Manchuria, to the Marianas, under Lt. Gen. Takeshi Takashima. The Japanese also sent the 29th Infantry Division under Maj. Gen. Kiyoshi Shigematsu. This was divided into the 48th Independent Mixed Brigade (2,800 men) and the 10th Independent Mixed Regiment of 1,900 men.
The Marianas came under the command of the 31st Army, under Lt. Gen. Hideyoshi Obata, who was on an inspection trip on Palau when he learned the Americans were invading Saipan. He rushed back at once but could only get as far as Guam and stayed there, sharing command with Takashima.
The Imperial Navy also had forces on Guam, the 54th Keibitai, consisting of 3,000 naval combat troops under Captain Yukata Sugimoto. The Japanese also had 1,800 men in two naval construction battalions that could be used as infantry and 2,000 men of the naval air force. Originally, the island held 80 bombers and 80 fighters, but all were lost. It all added up to 35,000 men, but only 19,000 of them could be seen as first-line combat troops. Static defenses included a powerful collection of weapons, including dozens of heavy guns and howitzers and 580 machine guns.
American naval forces came under Rear Admiral Richard L. Conolly and Task Force 53, and the ground forces under the 3rd Amphibious Corps, commanded by Marine Maj. Gen. Roy Geiger, a 59-year-old Guadalcanal veteran. Conolly, 52, had commanded invasion forces at Sicily and was known as “Close In” Conolly for his commitment to tight naval support of invasions.
The spear point of the corps was Maj. Gen. Allen Turnage’s 3rd Marine Division, which had fought on Bougainville. It had three regiments, the 3rd, 9th, and 21st Marines, and added up to 17,465 Leathernecks. The other corps asset was Brig. Gen. Lemuel Shepherd’s 1st Marine Provisional Brigade, which consisted of the 4th and 22nd Marine Regiments. The 22nd had suffered an outbreak of filariasis while training in Samoa which led to 1,800 transfers.
There was no designated backup for the two Marine units, but the Army considered its 27th Infantry Division, assigned to invade Tinian, and the 77th “Metropolitan” Infantry Division, originally drawn from New York City, to be the potential reserves. Ultimately, the 77th, under Maj. Gen. Andrew Bruce, was tapped for Guam.
The tactical plan for invading Guam was called Operation Stevedore and was drafted in April 1944. It set the invasion date for June 18, but the assault was postponed for a month due to the harsh fighting on Saipan.
Although Guam had been an American possession for 40 years, the United States had very little information about the island. Geiger asked for submarine patrols to contact Guamanians for up-to-date intelligence about Japanese deployments. His request was denied. The Americans would not have good maps of Guam until the invasion had begun, or even thereafter.
The Americans chose simplicity and daring for their invasion plans: the best place to land on Guam was Tumon Bay north of Agana. Both the Americans and Japanese knew this, and the Japanese defended the bay heavily. Geiger chose to contend with wide coral reefs and shallow water rather than Japanese gunfire. The 3rd Marine Division would attack at Agana, while the 1st Marine Brigade would storm ashore on the Agat beaches, surrounding the Apra Harbor and sealing off the Orote Peninsula.
Hitting the Beaches
As the Marines rehearsed the invasion, the Navy began softening up the defenders on Guam and pulverized the Imperial Japanese Navy in the Battle of the Philippine Sea. The Navy began shelling Guam on June 16.
Checking the weather, Conolly decided that W-day would be July 21, and H-hour would be 8:30 am. The invasion force left Eniwetok atoll bound for Guam on July 15 and arrived right on time. Weather conditions on W-day were perfect: clear with a slight overcast and a light wind. Early on the 21st, the Leathernecks loaded into their landing craft. Navy warships opened a massive bombardment at 5:30 am, joined by air support. At 6 am, the assault units were in position. The Navy began shelling the shore at 8:03 am.
The main Marine attack was directed at 2,000 yards of landing beach between Asan Point and Adelup Point, the 3rd Marine Regiment storming ashore at Red Beach 1, the 21st at Green Beach in the center, and the 9th Marines on Blue Beach. South of Orote Peninsula, the 4th Marines were to hit Beaches Yellow 1 and 2 and the 22nd Marines White Beaches 1 and 2. The Americans expected little resistance to the initial landings at Asan. When the bombardment lifted, they returned to their positions and opened fire on the 1st Provisional Brigade.
Even so, the Asan landings were successful. Within 40 minutes, the Leathernecks were moving. The 3rd Marine Regiment lost 231 killed and wounded. Once the Marines moved inland, the fighting grew tougher. The 3rd Marine Tank Battalion’s Shermans waddled up to support the riflemen, and flamethrowers joined the attack. Soon Chonito Cliff was taken.
The 1st Battalion, 3rd Marines also ran into trouble with machine-gun fire. Captain Geary Bundschu, commanding the battalion’s A Company, tried to flank the position but was unsuccessful. He sought permission to disengage but was refused. Instead, regiment ordered a second direct attack. Bundschu fell in the assault, and his company was pinned down all day. With all weapons firing, the Marines finally silenced the machine guns with hand grenades. The 2/3 Marines were slowed by determined defense, too. The Marines promptly named the hill “Bundschu Ridge.”
At Agat beach, the 1st Provisional Marine Brigade faced a wide coral reef and intense enemy fire. The Japanese were protected from the low trajectory naval guns by hills and caves. Japanese troops of the 38th Regiment poured rifle and machine-gun fire on White and Yellow Beaches. Invading landing vehicles were hung up on the coral reef and drew Japanese fire.
Despite the heavy fire, the 22nd Marines stormed ashore according to plan with DUKWs bringing in Sherman tanks. These blasted open strongpoints and rumbled toward Agat village against sporadic resistance.
The 4th Marines also landed on schedule and came under concentrated fire. The 2/4 Marines were halted by Japanese fire from a hill that was not on their maps and were pinned down until noon. The 1/4 Marines found safety in a drainage ditch before regrouping and defeating the Japanese.
General Shepherd himself came ashore at noon, finding the situation critical. Despite successes, his men were exhausted, thirsty, and short of ammunition and water. Communications were a mess. A Japanese counterattack might cause chaos. At 12:45 pm, the 1/22 Marines moved through the rubble of Agat with tank support and took the town.
Suenaga’s Last Charge
The Marines headed east to seize a hill, but the Japanese machine gunners were too determined to dislodge. The 4th Marines did not do much better, even with air support. With sunset coming, Shepherd knew the Japanese would launch ferocious night counterattacks and ordered his men to dig in.
Shepherd was right. Takashima was indeed planning night counterattacks, but his forces had suffered heavy casualties and his plans lacked cohesion. Colonel Tsumetaro Suenaga wanted to hurl two battalions at the 1st Marine Provisional Brigade at 5:30 pm. At first, Takashima demurred. Then he agreed. Before launching the attack, Suenaga ordered his regimental colors burned—a sign that his command would be destroyed. The attack went in at 11:30 pm with a heavy mortar barrage on the right flank of the 4th Marines. Half an hour later, Japanese troops accompanied by four clanking T-97 tanks hit the 3/4 Marines. The Americans replied with bazookas and 75mm shells from their Sherman tanks, setting the rivet-hulled T-97s ablaze and breaking up the attack.