The Guadalcanal Campaign, also known as the Battle of Guadalcanal and code-named “Operation Watchtower”, originally applying only to an operation to take the island of Tulagi, by Allied forces, was a military campaign fought between 7 August 1942 and 9 February 1943 on and around the island of Guadalcanal in the Pacific theater of World War II. It was the first major offensive by Allied forces against the Empire of Japan.
On 7 August 1942, Allied forces, predominantly United States (US) Marines, landed on the islands of Guadalcanal, Tulagi, and Florida in the southern Solomon Islands, with the objective of stopping the Japanese threatening Allied supply and communication routes between the US, Australia, and New Zealand. The Allies also intended to use Guadalcanal and Tulagi as bases to support a campaign to eventually capture or neutralize the major Japanese base at Rabaul on New Britain. The Allies overwhelmed the outnumbered Japanese defenders, who had occupied the islands since May 1942, and captured Tulagi and Florida, as well as an airfield (later named Henderson Field) that was under construction on Guadalcanal.
Surprised by the Allied offensive, the Japanese made several attempts between August and November to retake Henderson Field. Three major land battles, seven large naval battles, and continual, almost daily, aerial battles culminated in the decisive Naval Battle of Guadalcanal in early November, in which the last Japanese attempt to bombard Henderson Field from the sea and land with enough troops to retake it, was defeated. In December, the Japanese abandoned their efforts to retake Guadalcanal and evacuated their remaining forces by 7 February 1943, in the face of an offensive by the US Army’s XIV Corps.
The Guadalcanal campaign was a significant strategic combined arms Allied victory in the Pacific theater. Along with the Battle of Midway, it has been called a turning-point in the war against Japan.
On 7 December 1941, Japanese forces attacked the United States Pacific Fleet at Pearl Harbor, Hawaii. The attack crippled much of the U.S. battleship fleet and precipitated an open and formal state of war between the two nations. The initial goals of Japanese leaders were to neutralize the US Navy, seize possessions rich in natural resources, and establish strategic military bases to defend Japan’s empire in the Pacific Ocean and Asia. To further those goals, Japanese forces captured the Philippines, Thailand, Malaya, Singapore, Burma, the Dutch East Indies, Wake Island, Gilbert Islands, New Britain and Guam. Joining the U.S. in the war against Japan were the rest of the Allied powers, several of whom, including the United Kingdom, Australia and the Netherlands had also been attacked by Japan.
The Allies chose the Solomon Islands (a protectorate of the United Kingdom), specifically the southern Solomon Islands of Guadalcanal, Tulagi and Florida Island, as the first target, designated Task One, codenamed Pestilence, with three specific objectives. Originally the objectives were the occupation of the Santa Cruz Islands, codenamed Huddle, Tulagi, codenamed Watchtower, and “adjacent positions”. Guadalcanal (Code name Cactus), eventually the focus of the operation, was not even mentioned in the early directive and only later took on the operation name Watchtower.
The Imperial Japanese Navy (IJN) had occupied Tulagi in May 1942 and had constructed a seaplane base nearby. Allied concern grew when, in early July 1942, the IJN began constructing a large airfield at Lunga Point on nearby Guadalcanal—from such a base Japanese long-range bombers would threaten the sea lines of communication from the West Coast of the Americas to the populous East Coast of Australia. By August 1942, the Japanese had about 900 naval troops on Tulagi and nearby islands and 2,800 personnel (2,200 being Korean forced laborers & trustees as well as Japanese construction specialists) on Guadalcanal. These bases would protect Japan’s major base at Rabaul, threaten Allied supply and communication lines and establish a staging area for a planned offensive against Fiji, New Caledonia and Samoa. The Japanese planned to deploy 45 fighters and 60 bombers to Guadalcanal. In the overall strategy for 1942 these aircraft could provide air cover for Japanese naval forces advancing farther into the South Pacific.
The Allied plan to invade the southern Solomon’s was conceived by U.S. Admiral Ernest King, Commander in Chief, United States Fleet. He proposed the offensive to deny the use of the islands by the Japanese as bases to threaten the supply routes between the United States and Australia and to use them as starting points.
In preparation for the offensive in the Pacific in May 1942, U.S. Marine Major General Alexander Vandegrift was ordered to move his 1st Marine Division from the United States to New Zealand. Other Allied land, naval and air force units were sent to establish or reinforce bases in Fiji, Samoa, New Hebrides and New Caledonia. Espiritu Santo, New Hebrides, was selected as the headquarters and main base for the offensive, codenamed Operation Watchtower, with the commencement date set for 7 August 1942.
At first, the Allied offensive was planned just for Tulagi and the Santa Cruz Islands, omitting Guadalcanal. After Allied reconnaissance discovered the Japanese airfield construction efforts on Guadalcanal, its capture was added to the plan and the Santa Cruz operation was (eventually) dropped. The Japanese were aware, via signals intelligence, of the large-scale movement of Allied forces in the South Pacific area but concluded that the Allies were reinforcing Australia and perhaps Port Moresby in New Guinea.
The Watchtower force, numbering 75 warships and transports (of vessels from the U.S. and Australia), assembled near Fiji on 26 July 1942 and engaged in one rehearsal landing prior to leaving for Guadalcanal on 31 July.
The troops sent to Guadalcanal were fresh from military training and armed with bolt action M1903 Springfield rifles and a meager 10-day supply of ammunition. Because of the need to get them into battle quickly, the operation planners had reduced their supplies from a 90-days to only 60 days. The men of the 1st Marine Division began referring to the coming battle as “Operation Shoestring”.
Bad weather allowed the Allied expeditionary force to arrive unseen by the Japanese on the night of 6 August and the morning of 7 August, taking the defenders by surprise. This is sometimes called the Midnight Raid on Guadalcanal. A Japanese patrol aircraft from Tulagi had searched the general area the Allied invasion fleet was moving through, but missed seeing the Allied ships due to severe storms and heavy clouds. The landing force split into two groups, with one group assaulting Guadalcanal, and the other Tulagi, Florida, and nearby islands. Allied warships bombarded the invasion beaches while U.S. carrier aircraft bombed Japanese positions on the target islands and destroyed 15 Japanese seaplanes at their base near Tulagi.
Tulagi and two nearby small islands, Gavutu and Tanambogo, were assaulted by 3,000 U.S. Marines. The 886 IJN personnel manning the naval and seaplane bases on the three islands fiercely resisted the Marine attacks. With some difficulty, the Marines secured all three islands; Tulagi on 8 August, and Gavutu and Tanambogo by 9 August. The Japanese defenders were killed almost to the last man, while the Marines suffered 122 killed.
In contrast to Tulagi, Gavutu, and Tanambogo, the landings on Guadalcanal encountered much less resistance. At 09:10 on 7 August, Vandegrift and 11,000 U.S. Marines came ashore on Guadalcanal between Koli Point and Lunga Point. Advancing towards Lunga Point, they encountered little resistance and secured the airfield by 16:00 on 8 August. The Japanese naval construction units and combat troops, under the command of Captain Kanae Monzen, panicked by the warship bombardment and aerial bombing, had abandoned the airfield area and fled about 3 miles (4.8 km) west to the Matanikau River and Point Cruz area, leaving behind food, supplies, intact construction equipment and vehicles, and 13 dead.
During the landing operations on 7 and 8 August, Japanese naval aircraft based at Rabaul, under the command of Sadayoshi Yamada, attacked the Allied amphibious forces several times, setting afire the transport USS George F. Elliot (which sank two days later) and heavily damaging the destroyer USS Jarvis. In the air attacks over the two days, the Japanese lost 36 aircraft, while the U.S. lost 19, both in combat and to accident, including 14 carrier fighters.
After these clashes, Fletcher was concerned about the losses to his carrier fighter aircraft strength, anxious about the threat to his carriers from further Japanese air attacks, and worried about his ships’ fuel levels. Fletcher withdrew from the Solomon Islands area with his carrier task forces the evening of 8 August. As a result of the loss of carrier-based air cover, Turner decided to withdraw his ships from Guadalcanal, even though less than half of the supplies and heavy equipment needed by the troops ashore had been unloaded. Turner planned, however, to unload as many supplies as possible on Guadalcanal and Tulagi throughout the night of 8 August and then depart with his ships early on 9 August.
Battle of Savo Island
That night, as the transports unloaded, two groups of screening Allied cruisers and destroyers, under the command of British Rear Admiral Victor Crutchley VC, were surprised and defeated by a Japanese force of seven cruisers and one destroyer from the 8th Fleet based at Rabaul and Kavieng and commanded by Japanese Vice Admiral Gunichi Mikawa. In the Battle of Savo Island one Australian and three American cruisers were sunk and one American cruiser and two destroyers were damaged. The Japanese suffered moderate damage to one cruiser. Mikawa, who was unaware Fletcher was preparing to withdraw with the U.S. carriers, immediately retired to Rabaul without attempting to attack the transports. Mikawa was concerned about daylight U.S. carrier air attacks if he remained in the area. Bereft of his carrier air cover, Turner decided to withdraw his remaining naval forces by the evening of 9 August and in so doing left the Marines ashore without much of the heavy equipment, provisions and troops still aboard the transports. Mikawa’s decision not to attempt to destroy the Allied transport ships when he had the opportunity proved to be a crucial strategic mistake.
By 23 August, Kawaguchi’s 35th Infantry Brigade reached Truk and was loaded onto slow transport ships for the rest of the trip to Guadalcanal. The damage done to Tanaka’s convoy during the Battle of the Eastern Solomons caused the Japanese to reconsider trying to deliver more troops to Guadalcanal by slow transport. Instead, the ships carrying Kawaguchi’s soldiers were sent to Rabaul. From there, the Japanese planned to deliver Kawaguchi’s men to Guadalcanal by destroyers staging through a Japanese naval base in the Shortland Islands. The Japanese destroyers were usually able to make round trips down “The Slot” (New Georgia Sound) to Guadalcanal and back in a single night throughout the campaign, minimizing their exposure to Allied air attack. The runs became known as the “Tokyo Express” to Allied forces and were labeled “Rat Transportation” by the Japanese. Delivering the troops in this manner, however, prevented most of the heavy equipment and supplies, such as heavy artillery, vehicles, and much food and ammunition, from being transported to Guadalcanal with them. In addition, this activity tied up destroyers the IJN desperately needed for commerce defense. Either inability or unwillingness prevented Allied naval commanders from challenging Japanese naval forces at night, so the Japanese controlled the seas around the Solomon Islands during nighttime. However, any Japanese ship remaining during daylight hours within range of the aircraft at Henderson Field, about 200 miles (320 km), was in great danger from air attack. This tactical situation existed for the next several months of the campaign.
Between 29 August and 4 September, various Japanese light cruisers, destroyers, and patrol boats were able to land almost 5,000 troops at Taivu Point, including most of the 35th Infantry Brigade, much of the Aoba (4th) Regiment, and the rest of Ichiki’s regiment. General Kawaguchi, who landed at Taivu Point on 31 August Express run, was placed in command of all Japanese forces on Guadalcanal. A barge convoy took another 1,000 soldiers of Kawaguchi’s brigade, under the command of Colonel Akinosuke Oka, to Kamimbo, west of the Lunga perimeter.
Naval Battle of Guadalcanal
After the defeat in the Battle for Henderson Field, the IJA planned to try again to retake the airfield in November 1942, but further reinforcements were needed before the operation could proceed. The IJA requested assistance from Yamamoto to deliver the needed reinforcements to the island and to support the next offensive. Yamamoto provided 11 large transport ships to carry the remaining 7,000 troops from the 38th Infantry Division, their ammunition, food, and heavy equipment from Rabaul to Guadalcanal. He also provided a warship support force that included two battleships. The two battleships, Hiei and Kirishima, equipped with special fragmentation shells, were to bombard Henderson Field on the night of 12–13 November and destroy it and the aircraft stationed there in order to allow the slow, heavy transports to reach Guadalcanal and unload safely the next day. The warship force was commanded from Hiei by recently promoted Vice Admiral Hiroaki Abe.
In early November, Allied intelligence learned that the Japanese were preparing again to try to retake Henderson Field. Therefore, the U.S. sent Task Force 67, a large reinforcement and resupply convoy carrying Marine replacements, two U.S. Army infantry battalions, and ammunition and food, commanded by Turner, to Guadalcanal on 11 November. The supply ships were protected by two task groups, commanded by Rear Admirals Daniel J. Callaghan and Norman Scott, and aircraft from Henderson Field. The ships were attacked several times on 11 and 12 November by Japanese aircraft from Rabaul staging through an air base at Buin, Bougainville, but most were unloaded without serious damage.
U.S. reconnaissance aircraft spotted the approach of Abe’s bombardment force and passed a warning to the Allied command Thus warned, Turner detached all usable combat ships under Callaghan to protect the troops ashore from the expected Japanese naval attack and troop landing and ordered the supply ships at Guadalcanal to depart by early evening 12 November. Callaghan’s force comprised two heavy cruisers, three light cruisers, and eight destroyers.
Around 01:30 on 13 November, Callaghan’s force intercepted Abe’s bombardment group between Guadalcanal and Savo Island. In addition to the two battleships, Abe’s force included one light cruiser and 11 destroyers. In the pitch darkness, the two warship forces intermingled before opening fire at unusually close quarters. In the resulting mêlée, Abe’s warships sank or severely damaged all but one cruiser and one destroyer in Callaghan’s force and both Callaghan and Scott were killed. Two Japanese destroyers were sunk and another destroyer and Hiei heavily damaged. In spite of his defeat of Callaghan’s force, Abe ordered his warships to retire without bombarding Henderson Field. Hiei sank later that day after repeated air attacks by CAF aircraft and aircraft from the U.S. carrier Enterprise. Because of Abe’s failure to neutralize Henderson Field, Yamamoto ordered the troop transport convoy, under the command of Raizo Tanaka and located near the Shortland Islands, to wait an additional day before heading towards Guadalcanal. Yamamoto ordered Nobutake Kondō to assemble another bombardment force using warships from Truk and Abe’s force to attack Henderson Field on 15 November.
In the meantime, around 02:00 on 14 November, a cruiser and destroyer force under Gunichi Mikawa from Rabaul conducted an unopposed bombardment of Henderson Field. The bombardment caused some damage but failed to put the airfield or most of its aircraft out of operation. As Mikawa’s force retired towards Rabaul, Tanaka’s transport convoy, trusting that Henderson Field was now destroyed or heavily damaged, began its run down the slot towards Guadalcanal. Throughout the day of 14 November, aircraft from Henderson Field and Enterprise attacked Mikawa’s and Tanaka’s ships, sinking one heavy cruiser and seven of the transports. Most of the troops were rescued from the transports by Tanaka’s escorting destroyers and returned to the Shortlands. After dark, Tanaka and the remaining four transports continued towards Guadalcanal as Kondo’s force approached to bombard Henderson Field.
In order to intercept Kondo’s force, Halsey, who was low on undamaged ships, detached two battleships, Washington and South Dakota, and four destroyers from the Enterprise task force. The U.S. force, under the command of Willis A. Lee aboard Washington, reached Guadalcanal and Savo Island just before midnight on 14 November, shortly before Kondo’s bombardment force arrived. Kondo’s force consisted of Kirishima plus two heavy cruisers, two light cruisers, and nine destroyers. After the two forces made contact, Kondo’s force quickly sank three of the U.S. destroyers and heavily damaged the fourth. The Japanese warships then sighted, opened fire, and damaged South Dakota. As Kondo’s warships concentrated on South Dakota, Washington approached the Japanese ships unobserved and opened fire on Kirishima, smashing into the Japanese battleship repeatedly with both main and secondary battery shells, and causing fatal damage. After fruitlessly chasing Washington towards the Russell Islands, Kondo ordered his warships to retire without bombarding Henderson Field. One of Kondo’s destroyers was also sunk during the engagement.
As Kondo’s ships retired, the four Japanese transports beached themselves near Tassafaronga on Guadalcanal at 04:00 and quickly began unloading. At 05:55, U.S. aircraft and artillery began attacking the beached transports, destroying all four transports along with most of the supplies that they carried. Only 2,000–3,000 of the army troops made it ashore. Because of the failure to deliver most of the troops and supplies, the Japanese were forced to cancel their planned November offensive on Henderson Field making the results of the battle a significant strategic victory for the Allies and marking the beginning of the end of Japanese attempts to retake Henderson Field.
On 26 November, Japanese Lieutenant General Hitoshi Imamura took command of the newly formed Eighth Area Army at Rabaul. The new command encompassed both Hyakutake’s 17th Army and the 18th Army in New Guinea. One of Imamura’s first priorities upon assuming command was the continuation of the attempts to retake Henderson Field and Guadalcanal. The Allied offensive at Buna in New Guinea, however, changed Imamura’s priorities. Because the Allied attempt to take Buna was considered a more severe threat to Rabaul, Imamura postponed further major reinforcement efforts to Guadalcanal to concentrate on the situation in New Guinea.