Meanwhile the Japanese had continued to advance to the north coast of New Guinea and onto the Admiralty Islands, the Solomon Islands and pushed south seizing Tulagi and Guadalcanal, where they started construction of an airfield. The continued Japanese advance threatened the lines of communications from the United States to Australia and New Zealand. It also put a number of US bases in danger and so the Joint Chiefs of Staff came to the conclusion that an offensive in the Pacific was now vital. The 1st Marine Division was given the task of seizing Guadalcanal and the partially built airfield.
The Joint Chiefs met to discuss the matter and came up with a compromise. Ghormley would command the Tulagi part of the operation after which MacArthur would command the advance to Rabaul. The US Navy and Marine Corps would attack and seize Tulagi, Guadalcanal and the surrounding area while MacArthur made a parallel advance towards New Guinea. The boundary between Southwest Pacific and South Pacific was shifted to reflect the change and King notified Nimitz (and hence Ghormley) to start planning for an operation. Major General Alexander A Vandegrift was notified that his division (1st Marine Division) would spearhead the attack.
For Vandegrift, the news was far from welcome as he had not expected to go into action until sometime early in the new year and his division was spread out between Wellington and the United States, with part of it on garrison duty in Samoa. In just under a month he would have to make operational and logistical plans, unload his ships and reload them for combat, sail to the Fiji Islands to conduct a rehearsal and then sail to the Solomon Islands. Reconfiguring the division's supplies would have to be done in New Zealand's Aotoa Quay, a confined area that could only take five ships at a time. To make matters worse, the dock workers went on strike so that the Marines had to do the work themselves and the rains came which were driven by a cold persistent wind. Some food and clothing was lost due to being left unprotected in cardboard boxes that tended to disintegrate in such conditions. Finally it was discovered after the loading was complete that there was not enough room for all the motor transport to go aboard and so about three-quarters of the heavy prime movers were left behind. Vandegrift also had the problem of a serious lack of intelligence about Guadalcanal. The division's intelligence officer, Lt Col Frank B Goettge set up an extensive interview programme with former residents of the area to glean as much information as possible and a photo reconnaissance mission by Lt Col Merril B Twining and Major William B Kean yielded a large number of useful photographs of the north coast of the island. To protect the flanks of the main assault a number of smaller objectives on Florida Island, Gavutu, Tanambogo and others would be seized just prior to the main landing.
The American forces consisted mainly of the newly formed 1st Marine Division, which were untried volunteers, having to make do with World War One vintage equipment, having insufficient medical backup, communications and logistics to cope adequately with the harsh campaign. The American artillery was accurate and could deliver a large volume of high angle fire in either the defence or the attack. The Americans also used the M3A1 (Stuart) Light tanks they brought with them effectively. Both the Marines and the Army (who later came to augment and then relieve the Marines) learned valuable lessons in jungle warfare. When the Army came in force, it helped in overcoming the supply and medical problems that plagued the operation. The US Navy suffered at first around Guadalcanal but gradually learned its lessons and gained superiority over the Japanese. The one advantage the US Navy had was that, using a series of advanced operating bases, a ship sustaining damage could be repaired fairly quickly and sent into battle again, whereas the Japanese ships would have to retreat out of range of US airpower, which established itself on the island.
Having gained an extension to the proposed operation to complete preparations, the American task force split into two groups as it approached Savo Island in the early morning of 7th August 1942. The first group was designated X-RAY Guadalcanal and was made up of Combat Groups A and B and under the command od Vandegrift. Combat Group A consisted of the 5th Marine Regiment (Reinforced) minus its 2nd Battalion under Colonel Leroy P Hunt. Combat Group B consisted of the 1st Marine Regiment (Reinforced) under the command of Colonel Clifton B Cates. This force was to land on Guadalcanal while a smaller force, Y-OKE (Tulagi) captured objectives on Florida, Tulagi, Gavutu and Tanambogo. It consisted of the 1st Battalion, 2nd Marine Regiment under Major Robert E Hill which had the objective of Florida Island. Tulagi was to be assaulted by a group under Colonel Merrit A Edson with the (and who also commanded) the 1st Raider Battalion, as well as the 2nd Battalion, 5th Marines (Lt Col Harold E Rosecrans) and the 3rd Defense Battalion (Colonel Robert Pepper). The Gavutu and Tanambogo group consisted of the 1st Parachute Battalion under Major Robert H Williams. Y-OKE was under the command of Brigadier General William H Rupertus, the Assistant Divisional Commander. The division actually only had two regiments as the third regiment (7th Marines) had been assigned duties in British Samoa, but was not as weak as this situation implied as a number of specialised units had been added to augment it for this operation. This included the 1st Battalion, 2nd Marines (from the 2nd Marine Division), 3rd Defense Battalion, 1st Raider Battalion and 1st Parachute Battalion. There were in fact a total of 1,959 officers and 18,146 enlisted men and sailors in the amphibious landing force.
After the task force had set sail, the dress rehearsal in the Fiji Islands was called off due to bad conditions and so the task force continued on towards its objective. The amphibious force was being transported in nineteen transports and four destroyers, along with four cargo ships, eight cruisers, fourteen destroyers and five minesweepers. The carrier battlegroups were those of Saratoga, Enterprise and Wasp. The two amphibious groups separated as they approached Savo Island. The operations commenced with naval gunfire and naval aircraft support. The Tulagi attack started with the landing of Company B, 1st Battalion, 2nd Marines, near the village of Haleta on Florida Island. The landing was unopposed and the western flank quickly secured. The remainder of the battalion landed at Halavo on Florida Island at 08.45 to secure the eastern flank. The Tulagi assault went in on time at 08.00 with the 1st Raider Battalion going in first and the 2nd Battalion, 5th Marines following. The Marines started to make their way inland after landing with the Raiders moving east and the 2nd Battalion, 5th Marines moving north-west. The Raiders had to systematically overcome Japanese resistance as they advanced slowly and eventually dug in for the night. The Japanese launched four separate attacks to dislodge them but all failed and the Marines carried on to secure the island after overcoming a strong pocket of resistance in the north-east. The two small islands of Gavutu and Tanambogo were to be seized by two companies of the 1st Parachute Battalion, with a third company in reserve. The assault went in at H-Hour +4 (12.00) but the naval gunfire was so effective that the force had to be diverted as the original landing site was unusable. The new landing site to the north exposed the paratroopers to flanking fire from Tanambogo but they took the island and its hill with heavy casualties. Tanambogo had to be taken to secure Gavutu and so Company B, 1st Battalion, 2nd Marines reinforced the Paratroopers and attempted a night landing on Tanambogo but were repulsed. Finally, the 3rd Battalion, 2nd Marines with tanks from the 2nd Tank Battalion and naval gunfire support landed on Tanambogo and had secured it by the end of the 9th August.
On Guadalcanal, an unopposed landing was made at Beach Red, led by the 5th Marines who were followed by the 1st Marines. The 5th Marines were to move along the coast and the 1st Marines would move inland through the jungle and secure Mount Austen. It was found that Mount Austen was farther away than expected and so the landing was consolidated and supplies dispersed as they came ashore. The Japanese launched an air raid by eighteen Type 97 bombers and then one with Type 99 bombers, neither of which accomplished much. Vandegrift decided to attack the airfield the next day and set up a defensive perimeter.
The following day saw the Marines continue the advance and assault the airfield, which was in the last stages of construction. Virtually all of it was captured intact and only small pockets of resistance were met. The Marines captured a large amount of supplies, weapons, equipment and food. It was thought that the Japanese had been taken by surprise but the High Command were in fact well aware the Americans were coming and thinking it only a raid, ordered their troops into the hills until the Americans had left. The task force was then attacked by a force of some forty Japanese torpedo planes, but had already taken defensive measures as they had been forewarned by a Coastwatcher, Cecil J Mason (a member of an organisation started by Captain Eric Feldt of the Royal Australian Navy to report on Japanese activities).
In the meantime, Admiral Fletcher decided the carrier support group should be withdrawn due to operational losses to the aircraft and a shortage of fuel oil. A meeting was called between Turner, Vandegrift and Crutchley who arrived on one of his cruisers, removing a major warship from the screen. Once the carriers had gone, the transports would be without air cover and therefore could no longer remain. Vandegrift complained as half his supplies were still on the transports, but the decision stood. At this point the Japanese force was approaching Savo Island undetected. They launched float planes which flew over the Allied ships and then dropped illuminating flares. The Japanese ships had somehow slipped past the radar pickets and in the ensuing engagement, which was really a confused mêlée, the Japanese scored a major victory with the loss of four Allied cruisers, one cruiser and one destroyer damaged to the Japanese having a single destroyer damaged. This turned out to be one of the worst defeats suffered by the US Navy in the Second World War, but amazingly, Admiral Mikawa did not attack the transports but withdrew out of range of the carrier aircraft. The task force withdrew later that day (9th August).
The Marines therefore began to take stock of their situation and began to develop the airfield as any successful outcome would depend on the Americans having aircraft based on the island. It would not be until 20th August that the first planes landed from VMF-223 (nineteen F4F-4s) and VMSB-232 (twelve SBD-3s) which were followed by fourteen P-400s from Army Air Corps 667 Squadron (an export version of the P-40). For most of the campaign the Japanese launched incessant air raids, the target of which was either Henderson Field (the name of the airstrip under American control) or the resupply ships at Lunga Point. Japanese ships also bombarded the perimeter at night. The Marines started to improve the perimeter defences with Vandegrift concentrating the bulk of his force along the beach and defensive positions dug along 'Alligator Creek' in the east and south from Kukum to a low range of hills in the west.
After the defensive perimeter had been established three patrols were sent out to reconnoitre the main concentrations of Japanese troops. The first, nicknamed the 'Goettge' patrol was commanded by the Divisional Intelligence Officer, Colonel Frank B Goettge. It had its mission altered when the Marines learned that some of the Japanese might be persuaded to surrender. The patrol landed east of Point Cruz (instead of west of it) near the Matanikau River after leaving Kukum beach on 12 August. The patrol ran into a small force of Japanese and decided to dig in and signal for assistance instead of withdrawing. Two Marines, Sergeant Charles C Arndt and Corporal Joseph Spaulding were sent to get help but by the time they had reached the main perimeter the patrol had been overrun by increasing numbers of Japanese with only one Marine, Sergeant Frank L Few, surviving. The second patrol had better luck as it came across a Catholic priest who advised them that the Japanese had landed a force over to the east near Koli Point. This was verified by information from a Coastwatcher, Captain Martin Clemens of the British Protectorate Defence Force Solomon Islands, who had been feeding information back to Australia and who came out of hiding to help the Marines in establishing an intelligence network. The third patrol left on the 19th August to establish the strength of the Japanese and was led by Captain Charles C Brush. It ran into a large party of senior Japanese officers and NCOs who were reconnoitring the Marine lines for a probable attack and a firefight ensued.
Meanwhile, the Japanese were preparing to retake Guadalcanal. The 28th Infantry Regiment (7th Division, 17th Army) and the Yokosuka Special Naval Landing Force would land first with the 35th Brigade to follow. The reinforced 2nd Battalion (28th Infantry Regiment) commanded by Colonel Kiyono Ichiki landed at Taivu Bay on the night of the 18th August, while the troops of the Yokosuka Special Naval Landing Force landed west of Kokumbona. This operation was the first of what the Marines nicknamed the 'Tokyo Express' - a shuttle between Rabaul and Guadalcanal ferrying men, equipment and supplies. Ichiki was initially going to wait for the remainder of the regiment before moving and then move west and establish a headquarters at the former construction camp at Tenaru. However, upon learning that a Marine patrol had wiped out one of the scouting parties he had sent out on the 19th, he decided to attack with the forces he had. They marched west on the night of the 20th / 21st but the Marines had set up listening posts which detected the Japanese approaching and a sergeant in the native police, Jacob Vouza, stumbled into the base and warned them the Japanese were about to attack before collapsing having been tortured by the Japanese after they found an American flag on him. The Japanese attacked and attempted to overrun the 2nd Battalion, 1st Marines (Colonel Edwin A Pollock). The fighting was fierce but the Japanese could not dislodge the Marines. The next day the 2nd Battalion, 1st Marines, though battered, counterattacked along with the 1st Battalion, 1st Marines (the divisional reserve) and eliminated the last of Ichiki's force.
On 24th August, a major engagement between an American naval task force formed around Enterprise and Saratoga and a Japanese task force with five carriers, four battleships, sixteen cruisers and thirty destroyers occurred and became known as the Battle of the Eastern Solomons. The Americans turned back the Japanese task force sinking the carrier Ryujo, one destroyer, one light cruiser and damaging a seaplane carrier and another destroyer, but it managed to land reinforcements. The American carrier Enterprise had been damaged. On 31st August, Saratoga was torpedoed while the carrier Wasp was torpedoed and sunk on the 15th September with the battleship North Carolina sustaining serious damage. In the meantime the 1st Battalion, 5th Marines conducted an unopposed landing west of Point Cruz on 27th August. The battalion continued along the coast where it encountered resistance from Japanese troops who were well dug in. The battalion took moderate casualties due to the difficulties of manoeuvring in such restricted terrain, but before they could conduct an assault, the Japanese withdrew.
Things quietened down on Guadalcanal for a while, during which the Marine Air Wing began to establish itself at Henderson Field. Well into September, the Marines began to receive reports that the Japanese were fortifying the village of Tasimboko and it was decided to use the 1st Raider and 1st Parachute Battalions (who had been formed into a composite battalion due to combat losses) in a raid against the garrison on the 8th September. The operation would be led by Colonel Merrit A Edson and be conducted in two waves, the Raiders landing first, just east of the village. As the force moved west towards Tasimboko they met little resistance until just before the village itself. Here, a large number of Japanese were dug in and were well equipped and supported by field artillery. The Raiders attacked the village with an enveloping manoeuvre from the Paratroops and with air support from Henderson Field drove the Japanese out of Tasimboko. That the Marines were able to force the larger Japanese force to withdraw is due to the fact that it was actually the tail elements of the 35th Infantry Regiment commanded by Major General Kiyotaki Kawaguchi who had already formed it up to move against Henderson Field and the Japanese had spotted a resupply convoy heading for Lunga Point and assumed it was bring reinforcements to the raiding party.
The Raiders and Paratroops were put into a reserve defensive position south of Henderson Field on a series on grassey hills. The native scouts and Marine patrols sent out south of the airfield began to encounter increasing resistance and a Japanese offensive seemed likely. The attack (which became known as The Battle for 'Bloody Ridge') began on the 12th September with strong shelling from Japanese warships and a number of heavy probes from the south. The Kawaguchi Brigade (as it became known) struck repeatedly during the night and managed to establish a salient in the western part of the Marines' lines. The next day saw Edson attempt a counterattack which failed, and so the Marines strengthened their existing positions. They were repeatedly subjected to air attacks and Kawaguchi attacked with two infantry battalions that night, and succeeded in forcing the Marines from the southernmost positions and back into their final defensive line from which they succeeded in withstanding continuous Japanese attacks despite a number of flanking attacks being made on other parts of the perimeter. They were supported by artillery from close range and by aircraft from Henderson Field and eventually retook their original positions after being reinforced by the 2nd Battalion, 5th Marines on the 14th September.
The 1st Marine Division was reinforced by the arrival of their third regiment, the 7th Marine Infantry Regiment. They were transported from Samoa and it was decided to clear the Japanese from the Matanikau area with a reconnaissance in force by the 1st Battalion, 7th Marines who would move into the area between Mount Austen and Kokumbona. They would be followed by the Raiders who would attack the mouth of the Matanikau River and push on to Kokumbona.
The 1st Battalion, 7th Marines set out on the 23rd September under Lt Col Lewis B 'Chesty' Puller and made contact with a Japanese force near Mount Austen. General Vandegrift, fearing he had met a strong force, sent the 2nd Battalion, 5th Marines to reinforce him. Puller now sent two companies back with his casualties and the combined force continued to advance towards the Matanikau River and encountered Japanese fire from the west bank and controlling ridges. It found its way barred and could not force a crossing. Meanwhile the Raiders having set out to complete their part of the operation were tasked with moving south along the east bank to where the river forks and to find a crossing point. As the Raiders moved to a position they could ford the river they met a strong Japanese force which barred their way. A message from the Raiders was misinterpreted back at Headquarters which assumed they had succeeded and sent the two companies Puller had detached to evacuate the wounded in an amphibious assault to the west of Point Cruz to cut off any Japanese trying to withdraw along the coast. The landing was to be supported by the USS Ballard but fire support communications had been disrupted and no fire support was available. Fortunately the landing was unopposed but as the two companies moved inland they encountered a strong enemy column which was heading west from the river mouth. All three Marine forces were engaged and unable to support each other. The greatest danger was to the two companies near the coast as they were in danger of being surrounded but they managed to signal a passing dive bomber pilot, Lt Dale M Leslie, by using their T-shirts to spell 'HELP'. Puller decided on a rescue mission and managed to commandeer some landing craft. He came across the destroyer Ballard and boarded it, taking it along. When the destroyer showed up on station it cold not communicate with the Marines on shore but Sergeant Robert D Raysbrook exposed himself to enemy fire in order to signal the ship (earning him the Navy Cross and an equivalent medal from the UK). Under the cover of the destroyer's gunfire the Marines withdrew from the jungle and despite intense enemy fire, the landing craft reached the beach and picked them up. They were covered by Platoon Sergeant Anthony P Malinowsky Jr with a Browning Automatic Rifle (earning him a posthumous Navy Cross), Lt Leslie who had stayed in the air over the beach and Coast Guard Signalman 1st Class Douglas Munro, who manned a machinegun to cover the Marines. The remaining Marines pulled back to the perimeter.
Both sides made plans to push their front lines further towards the enemy with a view to denying (Marines) or enhancing (Japanese) artillery positions that could range in on Henderson Field. The Marines put their plan into operation first with the 5th Marines (minus one battalion) pushing towards the river in order to establish defensive positions on the eastern bank and the 7th Marines (minus one battalion but reinforced by the 3rd Battalion, 2nd Marines) crossing upstream and pushing north towards the village. The advance began on the 7th October and the 3rd Battalion, 5th Marines met a Japanese company-sized force and drove it westwards where they met a larger force which they managed to contain, despite numerous counterattacks. The Raiders reinforced the 3rd Battalion, 5th Marines and contained a major Japanese attack the next day. Meanwhile the main effort by the 7th Marines had been delayed by rain but started on the 9th October. They crossed the river and started to advance north when the 1st Battalion, 7th Marines came across a large Japanese force from the 4th Infantry Regiment encamped in a ravine. The Marines called artillery support and using all their available heavy weapons pounded the Japanese in the ravine and after heavy fighting withdrew after word of a counter offensive was received.
The Japanese 17th Army, under General Hakutake had been tasked to retake Guadalcanal with a combined Navy - Army operation, using the 2nd (Sendai) and 38th Divisions to augment the 17th Army. The counter offensive began with the Battle of Cape Esperance where a Japanese task force met an American force under Rear Admiral Norman Scott and which inflicted light losses on each other. This was followed by an intense aerial, artillery and sea bombardment of Henderson Field that effectively put the airfield out of operation. The Japanese then landed a large force at Tassafarongo Point. This force, combined with the forces already on the island, was to attack on the 22nd October in four prongs. The main attack would come from the south near 'Bloody Ridge' (under the command of Lt General Maruyama who would also be in overall command of the main attack), from the south-east between 'Alligator Creek' and 'Bloody Ridge' (Major General Kawaguchi) and from the south-west between Lunga River and 'Bloody Ridge' (Major General Nasu). The second attack was to come from the west over the Matanikau River and be supported by tanks (Major General Sumiyoshi). The third was to cross the Matanikau River upstream and assault the Marines holding a series of ridges east of the river (Colonel Oka). The fourth attack was an amphibious assault against Koli Point but it was cancelled when the Japanese thought American resistance was about to collapse. Movement through the jungle imposed delays upon the manoeuvring units and the elaborately timing of the attacks fell apart. Each was defeated in detail over the next three days, but the attacks, which were determined and prolonged, pushed the Marines to the limit and forced General Vandegrift to commit all his reserves, which included the newly arrived 3rd Battalion, 164th Infantry under Lt Col Robert K Hall. The month ended with the Battle of the Santa Cruz Islands at sea which resulted in losses of an aircraft carrier and a destroyer for the Americans, with another aircraft carrier, battleship, cruiser and destroyer being damaged. The Japanese sustained no losses but had three aircraft carriers and two destroyers damaged, but the Japanese were forced to leave the area.
On land, the 5th Marines led an attack over the high ground inland from the coast to finally clear the Matanikau area. The 2nd Marines (less the 3rd Battalion but with the 1st Battalion, 164th Infantry) would support the initial attack and would then continue the advance along the coastal road. The 3rd Battalion, 7th Marines would operate as flank protection. The attack began on the 1st November with the 1st and 2nd Battalions, 5th Marines up front and the 3rd Battalion trailing. The 1st Battalion, 5th Marines soon ran into heavy resistance from Japanese troops and became bogged down. The 3rd Battalion reinforced them and together with the 2nd Battalion began an outflanking move to isolate the Japanese. The 3rd Battalion itself ran into strong resistance, but all three battalions managed to overcome the main pocket of resistance and were reinforced by the 1st Battalion, 164th Infantry who arrived to help clear the area.
On the opposite side of the perimeter, the 2nd Battalion, 7th Marines (Colonel Herman H Hanneken) moved east to a position next to the Metapona River where they dug in. A Japanese battalion was landed quite near to their position and forces clashed on the 3rd November with the Japanese bringing down heavy artillery fire on the Marines who had been out of contact with headquarters and were forced to retire. The Japanese then managed to put a small force into their rear. Communications were then re-established briefly and General Vandegrift sent the 1st Battalion, 7th Marines to reinforce them and called for an airstrike to support. This went wrong however, and the aircraft instead bombed and strafed the Marines. Despite this, the 2nd Battalion, 5th Marines managed to withdraw to the Nalimbu River and under cover of Marine artillery and naval gunfire support held against Japanese attacks. After being reinforced, the two battalions began an eastward advance and were joined by the remainder of the 164th Infantry Regiment. By 9th November, the Americans had located a small Japanese force, which had established itself near Tetere to act as a rearguard for their main force, and by 12 November the US force had reduced this pocket. The 2nd Raider Battalion was also sent out at this time in a long-range mission to patrol the area around Mount Austen and destroy any Japanese artillery they could locate. Finally there were the naval actions of the Second Battle of Guadalcanal and the Battle of Tassafaronga in which there were few losses but the Japanese forces were turned back each time before they had completed their missions.
With the dawn of January 1943, General Patch decided to bring matters to a close on Guadalcanal by first clearing the area between Point Cruz and Kokumbona. He now commanded the XIV Corps with the 'Americal Division, 25th Infantry Division, 43rd Infantry Division and 2nd Marine Division. The 25th Infantry Division (minus the 35th Infantry Regiment and commanded by Major General J Lawton Collins) swept the hills just inland from the coast and cleared them in a four-day operation that included reducing a stubborn Japanese defensive position on the hills known as the 'Galloping Horse'. At this point, the 2nd Marine Division (under Brigadier General Alphonse De Carre) attacked along the coast road from Point Cruz against the 2nd (Sendai) Division with a view to obtaining a position to attack towards Kokumbona. Meanwhile the 35th Infantry was engaged in fierce fighting around the Gifu and the terrain feature known as the 'Seahorse'. The 1st and 3rd Battalions, 35th Infantry took the 'Seahorse' after a difficult fight, which left he 2nd Battalion, 35th Infantry with the task of taking the Gifu itself. The battle for it lasted for two weeks with the advance being made 100 yards at a time. It was recognised that tank support would be crucial but wasn't made available until near the end of the fighting. Finally, a double envelopment was launched and resistance began to crumble with the final shots being fired on the 23rd January. With the capture of the Gifu, 'Galloping Horse' and 'Seahorse' the 25th Infantry Division was able to clear the remaining hills around the southern flank and begin its drive towards Kokumbona. The village itself was captured by the 27th Infantry Regiment and the Japanese finally driven from the area. By the end of January all that was left for XIV Corps to do was to advance after the Japanese to drive them from the island completely.
In early February 1943 the Japanese decided to withdraw from Guadalcanal but increased their activity in order to fool US Intelligence into thinking they were going to prepare for another offensive. They would evacuate their remaining troops from Doma Cove and Cape Esperance and so landed a force of 600 troops to cover the withdrawal. Meanwhile the US XIV Corps had reached the Poha River and Kokumbona on the 25th January. The Combined Army and Marine (CAM) Division would attack west the next day with the 182nd Infantry advancing along the inland route and the 6th Marines along the coast, supported by artillery and the 2nd Marine Air Wing with the 147th Infantry in reserve. The CAM Division advanced over the Poha River and reached the Nueha River where it halted. At this point, General Patch detached the 147th Infantry and reinforced it with artillery from the 2nd Battalion, 10th Marines and the 97th Field Artillery Battalion and placed it under General De Carre to pursue the Japanese. The 147th Infantry advanced westwards, finally halting at the Bonegi River due to determined Japanese resistance. The Americans attacked the Japanese several times without success but the Japanese decided to withdraw on the 2nd February and so the advance continued to the Usamani River meeting little resistance. General Patch concluded that the Japanese were in fact planning to withdraw and so landed the 2nd Battalion, 132nd Infantry (under Colonel Alexander M George) on the north-west coast at Verahue on the 1st February where it could attempt to hit the Japanese in the rear and stop them escaping. They began their advance the next day and had reached Marovovo by the 7th February, the terrain and the lack of accurate intelligence about Japanese dispositions limiting their advance. Back on the north coast, the 161st Infantry (reinforced) took over from the 147th and resumed the pursuit. Both US forces continued their advance until they met at Tenaro village on the 9th February with not a Japanese soldier in sight. The Japanese had executed a skilful and cunning delaying action and had evacuated their forces on the nights of the 1st / 2nd, 4th / 5th and 7th / 8th February.
Nevertheless the first phase of the Solomons campaign had ended as a victory for the United States. It had been a hard fought campaign and had been a close-run thing. There were many moments when it could have swung either way but in the end the American victory had destroyed the myth of Japanese invincibility, validated the concept of amphibious warfare as taught and practised by the Marines (despite the memory of the failed attempt at Gallipoli in World War One) and created a seasoned cadre of veterans who could go back and teach in the United States or be used to form the basis of new units in the Pacific. Finally, the Americans had captured Guadalcanal itself which would be turned into one of the largest advanced naval and air bases in the western Pacific.