Not long after coming ashore, allied troops encountered a severe strain of dysentery; by mid-August one in five Marines was so inflicted. Next up for the Marines: malaria.
On the evening of 12 August, Lieutenant Colonel Frank Goettge, serving as the Division Intelligence Officer, led a 25-man patrol west of the Marine perimeter at Lunga Point. His intent was two-fold: first, to conduct a reconnaissance of the region, and second, to ascertain whether Japanese troops were willing to surrender to Allied forces. Soon after coming ashore, Japanese naval infantry attacked the patrol killing nearly every Marine. In response, on 19 August, General Vandegrift sent three companies of Marines from the 5th Regiment to attack the Japanese troop concentration west of the Matanikau River. One company attacked across the sandbar at the mouth of the river, while another crossed the river 1,000 meters inland and attacked the Japanese force at the Matanikau village. The third company landed by boat further west and attacked Kokumbuna village. Having thus killed 65 Japanese soldiers (losing four Marines), the battalion returned to the Marine perimeter.
On 20 August, two squadrons of Marine Corps fighter aircraft arrived at Henderson Field; one squadron of F4F Wildcats, and one of 12 SBD Dauntlesses. The Allied codename for these aviators was “Cactus Air Force.” Both squadrons were operational by the next morning and conducted daily raids on Japanese positions. Army aviators, flying the Bell P-400 Aircobra, arrived on 22 August.
As a response to the landing of Marines in the Solomon Islands, the Imperial General Staff ordered Lieutenant General Harukichi Hyakutake, who commanded Japan’s 17th Army (a corps-sized combat force) to retake Guadalcanal. Hyakutake would receive the support of naval units, including the combined fleet under Isoroku Yamamoto, then headquartered in Truk . At the time, 17th Army was heavily committed to the New Guinea campaign and had only a few organizations available to meet the Allied challenge. Of these, the 35th Infantry Brigade under Major General Kiyotake Kawaguchi was at Palau, the 4th (Aoba) Infantry Regiment was in the Philippines, and the 28th (Ichiki) Infantry Regiment (Colonel Kiyonao Ichiki, commanding) was aboard ship near Guam. As the closest unit to Guadalcanal, Colonel Ichiki’s command was the first to arrive, consisting of a battalion sized unit landing from destroyers at Taivu Point, east of the Lunga perimeter, at around midnight on 19 August. Without hesitation, the battalion began its march toward the 1st Marine Division positions that same night.
Apparently under-estimating the strength of the American Marines, the battalion commander ordered a frontal assault in the early morning hours of 21 August near Alligator Creek (also, Ilu River) on the east side of the Lunga perimeter. The Marines slaughtered the Japanese with heavy and interlocking fields of fire. This incident became known as the Battle of Tenaru. After daybreak, the Marines counter-attacked the Japanese force, once more inflicting heavy losses. In total, there were only 128 Japanese survivors; Colonel Ichiki was not one of them. The surviving Japanese made their way back to Taivu Point and notified 17th Army headquarters of their defeat; 17th Army headquarters ordered these survivors to “stand fast” and await further reinforcements.
Admiral Yamamoto took personal change of organizing the Japanese relief expedition. His intention was to destroy any American naval and land units operating in the area of the Solomon Islands. He wanted the use of the airstrip at Lunga Point. Taking most of his assault force from Truk, Japanese reinforcements began their movement to Guadalcanal on 23 August. On board the transport ships were the 1,500 remaining troops of the 28th Regiment and 500 men from the 5th (Yokosuka) Special Naval Landing Force. Guarding the troop carriers were 13 warships under the command of Rear Admiral Raizo Tanaka, who planned to land his force on 24 August. Admiral Yamamoto ordered Vice Admiral Chuichi Nagumo to provide cover for Tanaka’s landing force. Nagumo’s battle group included three carriers and 30 additional warships. It was Yamamoto’s plan to send the light carrier Ryujoahead of Nagumo’s main force as bait to attack the Marines at Guadalcanal and lure away American pilots. Nagumo’s carrier-based aircraft numbered 177.
Meanwhile, Admiral Fletcher’s Task Force 16 (two carriers —USS Saratoga and USS Enterprise) approached Guadalcanal to counter Japan’s counter-offensive efforts. The number of aircraft available to Fletcher was 176. The two battle groups clashed on 24 August. The Americans quickly overwhelmed Ryujo; the carrier went under during the night. Enterprise received enough damage to send her back to Hawaii for repairs , but the two Japanese fleet carriers escaped any damage. Japanese aircraft losses numbered in the dozens. The Americans lost only a handful of planes. In the end, both sides retreated from the area.
The Cactus Air Force attacked Tanaka’s ships on 25 August, sinking one transport, inflicting heavy damage on other ships, and forcing Tanaka to divert his force to the Shortland Islands in the northern Solomons. There, Tanaka transferred his surviving troops to destroyers for delivery to Guadalcanal. While the CAF attacked Tanaka, additional Japanese aircraft attacked Henderson Field, causing a great deal of chaos. Subsequently, Marine aircraft again targeted Tanaka’s task force, sinking one transport, rendering one destroyer incapable of further service, and damaging Tanaka’s own flagship, Jintsu. Once again, the Americans forced Tanaka to withdraw and reschedule his landing for 28 August.
Major General Kawaguchi’s brigade reached Truk on 23 August. Initially, the Japanese decided to load these troops onto slow transport ships for movement to Guadalcanal, but after the damage done to Tanaka’s convoy, Japanese planners put together a new plan. Rather than loading these troops onto slow transports for delivery to Guadalcanal, they decided to load these troops on to destroyers and transport them quickly through the New Georgia Sound (also called “The Slot”) to Guadalcanal. A destroyer could make the round trip in a single night and it was a strategy that minimized Japanese exposure to Allied air attack. The Americans referred to these overnight runs as the “Tokyo Express;” the Japanese called it “Ratto Yuso”(ラット輸送), or “rat transportation.” The downside to this operation was that it denied to the Japanese infantry most of its heavy equipment (vehicles, heavy artillery, tanks, and much food and ammunition). Moreover, the strategy reduced the availability of Japanese destroyers to escort and protect resupply convoys.
Between 29 August and 4 September, Japanese light cruisers, destroyers, and patrol boats landed 5,000 soldiers at Taivu Point, including most of the 35th Infantry Brigade, most of the 4th Infantry Regiment, and the balance of Colonel Ichiki’s regiment. General Kawaguchi came ashore on 31 August and assumed command of all Japanese forces on Guadalcanal. An additional 1,000 troops under Colonel Akinosuke Oka landed at Kamimbo, west of the Lunga Perimeter.
Throughout the month of August, small numbers of US aircraft and their crews arrived at Guadalcanal. By the end of August, the CAF had 64 planes of various types stationed at Henderson Field. On 3 September, Brigadier General Roy Geiger, Commanding General, 1st Marine Aircraft Wing, arrived and assumed command of all air operations at Guadalcanal. Air battles between Allied aircraft at Henderson Field and Japanese fighters and bombers from Rabaul became a daily occurrence. The opposing air elements were evenly matched. Between 25 August and 5 September, the Japanese lost 19 aircraft; the Americans lost 15. The difference, however, was that the Americans recovered more than half of their downed aircrews to fight again, while none of the Japanese aircrews survived. The Japanese learned that it was much more difficult to replace aircrews than it was aircraft.
General Vandergrift continued to strengthen and improve his defensive perimeter around Lunga Point. Between 21 August and 3 September, Vandergrift relocated three battalions from Tulagi and Gavutu to Guadalcanal. These were the 1st Raider Battalion under LtCol Merritt A. Edson, 1st Battalion, 5th Marines, and the 1st Parachute Battalion. This latter battalion had suffered significant casualties during the Battle of Tulagi and Gavutu-Tanambogo and remained seriously understrength. Accordingly, Vandergrift placed the 1st Parachute Battalion under Edson’s overall command. After fighting on diminished rations for nearly a month, the Guadalcanal Marines received much needed supplies between 23 August and 8 September.
On 1 September, U. S. Navy Seabees arrived on Guadalcanal and immediately set out to improve and maintain Henderson Field. Once the airfield could accommodate larger aircraft, Marine Aircraft Group 25 began flying in high priority cargo, such as personnel replacements, aviation gasoline, munitions, and medical supplies.
On 7 September, General Kawaguchi issued his directive to subordinate commanders: rout and annihilate the enemy in the vicinity of the Guadalcanal Island airfield. He intended to split his force into three elements, to approach the Lunga Perimeter inland, and then execute a surprise frontal assault (night attack). Oka’s troops would attack the perimeter from the west, while Ichiki’s remaining echelon (renamed Kuma Battalion) would attack from the east. Kawaguchi’s assault would be the main-body attack, numbering 3,000 men in three battalions. March to contact began on the same day.
Native scouts under the direction of coast watchers send reports to the Americans outlining the activities of Japanese troops at Taivu. Colonel Edson was planning a raid on the Japanese concentration at Taivu. To better assess the situation, he sent a reconnaissance patrol by boat to Taivu. On 8 September, after coming ashore, Edson’s men captured the village of Tasimboko, driving the Japanese into the jungle. Inside the village, Marines discovered large stockpiles of food, ammunition, medical supplies, and a powerful shortwave radio. The Marines destroyed what they could of the equipment and carried back with them to Lunga Point some documents and equipment. The Marines thus knew what was in store for them.
Colonel Edson and the Division Operations Officer assumed (correctly) that the Japanese attack, when it came, would come at the narrow, grassy, ridge that ran parallel to the Lunga River, just south of Henderson Field. Lunga Ridge offered a natural avenue of approach to the airfield, commanded the surrounding area, and (at that time) was relatively undefended. On 11 September, Edson moved his 800-man battalion onto and around the ridge.
The next night, Kawaguchi’s 1st Battalion assaulted the Raiders, forcing one Marine Company to withdraw to its secondary positions. The Japanese disengaged before sunrise. On 13 September, Kawaguchi faced Edson’s Raiders with 3,000 troops and an assortment of light artillery. The Japanese attack began just after nightfall with the 1st Battalion assaulting the Marine right flank west of Lunga Ridge. After breaking through the Marine lines, the Japanese attack faltered when additional Marines reinforced the perimeter. Two companies of Kawaguchi’s 2nd Battalion charged the southern edge of the ridge and pushed the Marines back to Hill 123 at the center section of the ridge. Marines at this position, supported by artillery, defeated wave after wave to Japanese frontal assaults. Hand-to-hand combat ensued. Marines also defeated Japanese units that had successfully infiltrated past the ridge to the edge of the airfield and assaults initiated by the Kuma and Oka Battalions. With more than 850 men killed in action, Kawaguchi led his shattered brigade in a five-day march westward to the Matanikau Valley where he joined up with what remained of Oka’s Battalion. Marines losses were 104 killed in action.
When the Japanese General Staff learned of Kawaguchi’s defeat, they concluded that Guadalcanal could be the decisive land battle of the war. Lieutenant General Hyakutake realized that in order to send additional (sufficient) troops and materials to defeat the Allied forces on Guadalcanal, he could not (at the same time) support operations in New Guinea. With the concurrence of the JGS, Hyakutake prepared to move greater numbers of troops to Guadalcanal for another attempt to take the airfield and defeat the American Marines.
Continued Next Week
- Braun, S. M. The Struggle for Guadalcanal (American Battles and Campaigns). New York: Putnam, 1969
- Christ, J. F. Battalion of the Damned: The 1st Marine Paratroopers at Gavutu and Bloody Ridge. Annapolis: Naval Institute Press, 2007
- Coggins, J. The Campaign for Guadalcanal: A Battle That Made History. Garden City: Doubleday, 1972.
- Hersey, J. Into the Valley: Marines at Guadalcanal. Lincoln: University of Nebraska Press, 2002
 Truk (now Chuuk Lagoon) is a sheltered body of water 1,100 miles north-east of New Guinea, now part of the Federated States of Micronesia. The atoll consists of a protective reef extending some 140 miles in diameter, enclosing a natural harbor 49 by 31 miles and an area of 820 square miles. Its land area is 36 square miles. During World War II, heavily fortified (most fortified of all Japanese strongholds) Truk was Japan’s main naval base in the South Pacific and served as Japan’s forward anchorage. Japanese engineers had constructed roads, trenches, bunkers, and a network of caves. The island contained five airstrips, seaplane bases, a torpedo boat station, submarine repair shops, a communications center, radar station, significant coastal defense batteries, and nearly 45,000 Japanese sailors and soldiers. The Truk (Chuuk) Islands is part of the larger Caroline Islands group.
 Enterprise transferred its aircraft to Henderson Field to reinforce the CAF. These reinforcing aircraft made daytime resupply of Japanese forward positions nearly impossible. In only a few weeks, the Japanese lost its air superiority to the Americans.
 This term was not used to denigrate the Japanese troops; the term was used because, like a rat, the Japanese ships were active only at night.