The Guadalcanal Campaign (aka Battle for Guadalcanal) in the Solomon Islands was a series of land, air, and sea battles between US and Japanese forces in the Pacific War of WWII. Lasting from August 1942 to February 1943, the campaign was a titanic struggle for control of Guadalcanal Island and its vital airstrip. The landing of tens of thousands of US Marines aimed to stop further Japanese expansion into the South Pacific and follow up the US victory at the Battle of Midway, but a large amphibious landing of Japanese forces and tit-for-tat naval encounters meant the final US victory came at a cost of over 6,000 US casualties and the loss of 24 ships, including the aircraft carrier Hornet.

Even before the Second World War (1939 to 45) began, the Japanese military government had been steadily expanding the Japanese Empire in East Asia and the Pacific region. By 1941, Japan controlled territories from Northern China to Thailand. In December 1941, Japanese carriers sent aircraft to attack Pearl Harbor, in Hawaii, home of the US Pacific Fleet. The plan was the brainchild of Admiral Yamamoto Isoroku (1884 to 1943), Commander-in-Chief of the Combined Fleet. Yamamoto realised the US was the greatest threat to Japan's ambitions in the Pacific and he wanted a pre-emptive strike of such magnitude that it would give Japan time to consolidate its defences and perhaps even push the US into a peace deal.

Achieving complete surprise, the attack on Pearl Harbor caused over 3,500 casualties and destroyed or seriously damaged 18 ships, including eight battleships. Crucially, no US carriers were in harbour that day. The US President Franklin D. Roosevelt (1882 to 1945) responded by declaring war on Japan. That same December, Japan launched attacks on the US-controlled Philippines, and British-controlled Malaya, Burma (Myanmar), and Hong Kong. Singapore was captured in February, and the Dutch East Indies were attacked in March and April 1942.

The US and Japanese navies clashed in the Battle of the Coral Sea in May 1942. The Japanese navy here attempted to occupy the Solomon Islands and the eastern part of Papua, but the US Navy was determined to prevent further Japanese expansion in the region and defend its supply routes from Australia. In the battle, the Japanese lost the light carrier Shōhō while the US lost the carrier Lexington.

The next encounter was at the Battle of Midway in June, a much more decisive engagement. As Japan attempted to invade the Midway Atoll, a US military base at the time, the US Pacific fleet responded and sank four Japanese aircraft carriers for the loss of only one US carrier, the Yorktown. The Imperial Japanese Navy had suffered its first major defeat since the 16th century and was now obliged to go on the defensive in the Pacific War. This did not mean the Japanese land forces followed suit. Indeed, US reconnaissance on 4 July revealed the Japanese were steadily building an airstrip on Guadalcanal in the Solomon Islands.

On 7 August 1942, US forces launched an attack on the Solomons, seven islands of which were now occupied by Japanese forces. The overall commander was Vice-Admiral Robert L. Ghormley (1883 to 1958), Commander-in-Chief South Pacific Area. The tactical commander was Vice-Admiral Frank Jack Fletcher (1885 to 1973), veteran of the battles of the Coral Sea and Midway. The plan was to perform an amphibious landing on Guadalcanal, the main island of the Solomon group, depositing 19,000 US Marines under the command of Major-General Alexander Vandergrift (1887 to 1973). The slow-moving amphibious fleet was protected by three aircraft carriers (Enterprise, Saratoga, and Wasp) and an escort of warships. In all, 82 ships were involved in the operation, which achieved its objective of surprise.

The first wave of Marines landed without much resistance except on the islets of Gavutu-Tananbogo. As planned, the strike had been launched before the Japanese forces, composed of around 2,200 personnel, could properly fortify the islands and before they had completed an airstrip. The US forces now had control of the vital airstrip, and engineers hastened to make it operational. The Imperial Japanese Navy responded to the attack by sending a strike force from their base at Rabaul on nearby Papua. The naval force was commanded by Vice-Admiral Mikawa Gunichi (1888 to 1981), who was given additional support from the airbase on Rabaul. The Japanese bombers sent to the Solomons were spotted by an Australian coast watcher, and so the effectiveness of this first attack was limited.

Gunichi's naval task force had more success off the coast of Savo Island and defeated a US screening force on 9 August. The Japanese used torpedoes to sink three US cruisers and the Australian cruiser Canberra, and damage two destroyers and another cruiser for the loss of only one destroyer. This new threat, and the fact his ships were low on fuel, caused Fletcher to withdraw his carriers from the area, which, in turn, obliged the amphibious carriers to also withdraw. The result was that not all the men or supplies that had been scheduled to land were, leaving the Marine invasion force without reserves of men or supplies, without most of their heavy equipment and ammunition, and without sufficient air support.

With no opposition at sea, the Japanese were able to land a force unopposed on Guadalcanal. This army, the Seventeenth Army, was led by Lieutenant-General Hyakutake Haruyoshi (1888 to 1947), and it was tasked with removing the Marines from the island. On 18 August, the Japanese general attempted to take control of the airstrip (now called Henderson Field) but, underestimating the size of the enemy force, he did not commit the entirety of his own army. This would be a recurring feature of the campaign. The entire attack force of 900 Japanese soldiers was wiped out in the Battle of Tenaru River. The airfield became operational from 20 August, and this allowed the US to build up aircraft on the island.

At sea a few days later, US aircraft sank the Japanese carrier Ryujo on 24 August, delaying a Japanese landing in the Eastern Solomons. On 30 and 31 August, the US aircraft carrier Saratoga was badly damaged in a Japanese torpedo counterattack. Vice-Admiral Fletcher was himself injured in what became known as the Battle of the Eastern Solomons.

Several more land battles followed as both sides competed for control of Henderson Field. As Major General Collins notes, the terrain was as difficult as the enemy's tenacity:

It was jungle fighting, but not entirely because Guadalcanal is a rather rough volcanic island and the ridges were covered normally with tall grass…this grass had been burnt off so the ridge lines were clear and the jungle was down in the valleys…It was very tough fighting because these ridges were not very broad and furthermore the Japanese were tough fighters and they would never give up. We had isolated a Japanese regiment as a strong point and they fought until we actually had to annihilate them. We used loudspeakers after we had surrounded them and tried to persuade them to surrender but they wouldn't.

(Holmes, 249 to 50)

The Marines were gradually reinforced, and they were able to extend their area of control over the coming months. The Japanese were also able to send reinforcements and supplies by airdrop and by sea, withdrawing troops from other theatres of the Pacific War and sending them with such regularity to Guadalcanal that the US soldiers nicknamed the operations the 'Tokyo Express'. Both sides, then, significantly reinforced the troops in the Solomons so that by the closing stages of the campaign, Japan fielded 25,000 personnel and the US 50,000.

On 12 September, another major Japanese push to grab the airfield, this time involving 6,000 troops, failed. Attacking in three zones, the closest the Japanese came to the airstrip was at the Battle of Bloody Ridge (aka Edson's Ridge). Here, the lack of resources of the defenders was telling. Just 800 US Marines managed to defend Lunga Ridge, and their commander, Lieutenant Colonel Merritt Edson, received the Medal of Honor for his leadership. Edson had at one stage rallied some of his retreating troops by declaring, "The only difference between you and a good marine is you're going in the wrong direction" (Holmes, 248). The attacking Japanese, who at one point reached within 3,000 feet (900 m) of the airstrip, had been pushed back. Even in defeat, the Japanese troops could cause further casualties since it was common for wounded soldiers to pretend they were dead, await the close inspection of US soldiers, and then blow everyone up with a grenade.

Undeterred by the resistance of the US forces, the Japanese launched yet another offensive on 23 October. This attack involved a naval bombardment from offshore battleships and another army division landing on Guadalcanal, but it was badly coordinated and ultimately failed. The Marines, meanwhile, had been reinforced by the addition of 3,000 men of the Americal Division.

The constant resupply of men and material by sea had led to several more major naval engagements, most of them at night. On 15 September, the US carrier Wasp was sunk and the battleship North Carolina was badly damaged. In the Battle of Cape Esperance on 11 to 12 October, US ships sank a Japanese heavy cruiser and damaged another, and sank a destroyer. US bombers then sank another two enemy destroyers. In this battle, the US forces lost a destroyer. After the battle, a new Commander-in-Chief South Pacific was selected, Vice-Admiral Halsey (1882 to 1959), who was much more aggressive than his predecessor Ghormley.

The Japanese were tenacious in their bombardment of Henderson Field. In just one night, 13 October, two battleships, Haruna and Kongo, bombarded the airstrip with 900 shells. Still the US Marines held out, but the US Navy would have to ensure such a bombardment did not happen again.

The Battle of Santa Cruz was fought between 24 and 26 October between the aircraft of each side's carriers. The Japanese managed to sink the carrier Hornet and damage the Enterprise, although they lost more aircraft in the battle, 100 to the US's loss of 74. More significantly, bomb hits on the decks of the Japanese carriers Shokaku and Zuiho put both of the Japanese carriers temporarily out of action in terms of launching planes.

Neither side was giving up. In the first week of November, the US forces on Guadalcanal were reinforced by an extra Americal division (6,000 men) and two more regiments of Marines. In mid-November, the Japanese land force was further reinforced by sending another 2,000-man infantry division in eleven transports. Although this amphibious landing benefitted from a large naval escort, US ships attacked it on 12 November. This night engagement is sometimes called the Battle of Guadalcanal. In one intense 30-minute clash, the Japanese lost three ships and the Americans six. Japanese cruisers then proceeded to bombard the airstrip from the sea. With the coming of daylight, US bombers sank one Japanese cruiser, heavily damaged three more, and then sank seven of the troop transports. The advantage the US had in possessing the airstrip was crucial to the outcome of the campaign.

On 13 November there was another naval battle in which the Japanese lost one battleship and one destroyer, and the Americans lost two cruisers and four destroyers, while one battleship was badly damaged. Two US admirals were killed in the battle. Revenge was gained the next day when the Japanese battleship Hiei was sunk. As night fell on 14 November, the battleship Kirishima was sunk by accurate radar-controlled fire from the US battleship Washington. In the same battle, three US destroyers and one Japanese destroyer were sunk.

Through the rest of November, the Japanese forces on the island could eventually only be safely resupplied by submarine. A final attempt to use surface vessels on 30 November revealed the dangers. A US Navy force of five cruisers and six destroyers attacked the Japanese ships but actually came off worse thanks to the enemy's skill using torpedoes. One US heavy cruiser, the Northampton, was sunk and three more damaged while the Japanese lost one destroyer in an engagement that became known as the Battle of Tasafaronga. Crucially, though, the Japanese were not able to adequately resupply their troops on the island. In December, the US land troops, in contrast to the struggling Japanese, were relieved by another full infantry division.

Command of the US land force was now given to Major-General Alexander Patch (1889 to 1945), and he launched an offensive against the weakening enemy in January 1943. Aside from a lack of supplies, many of the Japanese were suffering from diseases of one sort or another. Eventually, in an impressive feat of logistics, the Japanese force, around 10,650 men, was evacuated onto 58 destroyers on the nights of 1, 4, and 7 February. The battle was over. The US had suffered 6,111 casualties (of which 1,752 were killed), but they had finally gained control of Guadalcanal. The Japanese suffered around 24,000 men killed.

The US victory at Guadalcanal, along with the successful joint US-Australian operation on Papua, "had lifted the threat to Australia and the lines of communication, and had wrested the strategic initiative from the Japanese" (Smurthwaite, 91). The cost had been high. Over six months of fighting, the US had lost two aircraft carriers, eight heavy cruisers, and 14 destroyers. The Japanese had lost one aircraft carrier, two battleships, four cruisers, eleven destroyers, and six submarines. They had also lost the cream of their experienced fighter and bomber pilots.

The Guadalcanal Campaign, which had involved around 50 clashes on land and sea, had been one of attrition, the type of warfare Japan could not win against the USA. The economic, industrial, and military might of the US was most clearly demonstrated with the construction of 14 Essex-class carriers in 1943. Through that year and 1944, Japanese forces, fighting tenaciously, were gradually pushed back to hold only the home islands. Japan finally surrendered after the bombing of Hiroshima and Nagasaki in August 1945.