The Pacific War began in 1941 after the Japanese airstrike at Pearl Harbor. The airstrike ensured the loss of hundreds of U.S. aircraft and a number of American battleships. The Allies would make a slow start in this war as the Japanese armies advanced in the Pacific during 1942.
The first notable Allied victories would also be won at sea. The Battle of Coral Sea was the first naval battle to involve Japanese and American aircraft carriers off Port Moresby. Port Moresby was Japan’s target, but the withdrawal of Japan’s fleet during this battle ensured that it remained with the Allies. However, Allied celebrations were muted by the loss of one their aircraft carriers during this battle.
More U.S. aircraft carriers still remained at sea, so long as that was the case further Japanese advances in the Pacific were somewhat less likely. As such, American aircraft carriers were among the foremost targets of the Imperial Japanese Navy. At Midway Island the IJN expected to trap these carriers and take Midway.
With four aircraft carriers the Japanese went ahead with the operation, only to find three U.S. carries had arrived at Midway earlier than expected. The Americans were well-informed of the Japanese plans, so arrived shortly after the Japanese. The Japanese remained unaware of exactly how many U.S. aircraft carriers they were up against, as unlike the Americans they had not deciphered Allied codes.
The battle itself ended in defeat for Japan. U.S. bombers sank four Japanese aircraft carriers, along with hundreds of supported aircraft. Midway Island remained out of reach of the Japanese, and so the Allies had won a notable victory.
Buoyed by their victory at Midway, the Allies now began planning ground operations to advance in the Pacific. Having been informed that the Japanese were constructing an airbase at Guadalcanal, taking this airfield and the rest of Guadalcanal emerged as one of the first objectives for the Allies. If taken Guadalcanal could then be a base for further Allied operations in the Pacific.
It was on August 7 that the Allies first began landing troops at Guadalcanal. The objective for the U.S. marines was to seize a recently constructed Japanese airfield at Lunga Point, otherwise Henderson Field. The Americans captured and occupied Henderson Field the next day.
Naval action would be a big aspect of the Guadalcanal Campaign. The first of these naval battles would be the Battle of Savo Island. It was there that a Japanese fleet torpedoed American cruisers. The Americans lost the Canberra, Astoria, Quincy and Vincennes cruisers in action. In comparison, the Japanese fleet lost little; so this was a notable naval battle victory for the Imperial Japanese Navy.
On August 18, the Japanese landed reinforcements at Guadalcanal to defeat the American Marines. They would meet in battle at Tenaru (Ilu) River. During this battle the Americans slowly pushed the Japanese back towards the sea.
A renewed Japanese advance on Henderson Field emerged to the south of the airfield. However, this failed to take Henderson Field. After this defeat the Japanese moved thousands of more troops to Guadalcanal to defeat the U.S. Marines. In the weeks after the battle the Americans also received reinforcements.
The decisive battle during the Guadalcanal Campaign was the Battle for Henderson Field. After weeks of re-enforcing, thousands of Japanese and American troops met around the outskirts of Henderson Field. If the Japanese could have taken Henderson Field, then they would have gained air superiority and potentially wiped out the Allied naval presence from the air, as well as Marines on the ground.
The occupation of this airfield gave the Marines a notable advantage in the Guadalcanal Campaign. With this airfield supplies could be airlifted to them, as well as potential reinforcements. It also provided a base for U.S. military aircraft from where they could give their troops on the ground further air support.
Thus, the Japanese made a number of advances to retake Henderson Field. They sent in further reinforcements via the sea, but despite this the Marines held firm. By October the Japanese army had lost thousands of soldiers within Guadalcanal as they ran into a larger number of U.S. troops that originally anticipated.
Yet the Japanese army still had thousands of troops in Guadalcanal, 7,000 of which they moved through the jungle to strike at the southeast perimeter of Henderson Field. The army expected the troops of the Sendai Division could then draw the Marines to the east.
On the 24th the Sendai Division approached Henderson Field from the south with a right and left-wing. The two wings were disorganized, with the right-wing separated from the left. The left-wing was the first to arrive at the designated targets and overran the first knoll. However, they could not effectively penetrate further Marine lines established around the airfield.
By the next evening, the right-wing of the Sendai Division began to approach for a second strike. But during the brief interlude the U.S. Marines had also redeployed and reinforced their positions at Henderson Field with additional U.S. Army units. As such, the Japanese could not effectively penetrate Henderson Field's southern perimeter.
Along the western perimeter Japan also had another unit, which by the 26th arrived at the Matanikau River. It was here that it advanced some way up a ridge along the eastern side of the river, but the the soldiers could not hold their positions after U.S. troops counter-attacked. Consequently, they were later pushed back off the ridge.
That was the end of the Battle of Henderson Field. Hereafter, remaining Japanese troops withdrew. They had lost more than 3,000 soldiers, more than 10 times the number of U.S. Marines and infantry lost during the battle.
The Naval Battle of Guadalcanal was perhaps the decisive naval engagement of the campaign. To retake Henderson Field, Japan sent a transport convoy with thousands of reinforcements escorted by battleships, heavy cruisers and destroyers. The USA intercepted the transport convoy with a carrier, a couple of battleships and cruisers. During two naval battles that followed, Japan lost most of its supplies and troops expected to retake Henderson Field.
By 1943 it had become clear that Japan had lost the Guadalcanal Campaign. As such, the orders had been given to begin withdrawing Japanese troops. Thousands of Japanese troops were withdrawn from Guadalcanal during the early months, and by February the campaign was all but over.
The campaign was a notable strategic victory for the Allies. Not only had Japan lost crucial airfields to the Americans, it also ended the possibility of Japanese troops landing in Australia. The USA has preserved a vital supply route, and Guadalcanal would provide a base for further Allied operations in the Pacific.