The United States declared war on the Empire of Japan on December 8, 1941, the day after the Pearl Harbor attack. With both the German Reich and the Kingdom of Italy declaring war on the United States in retaliation, the country was faced with a conflict that had to be fought on the two opposite sides of the world. Although the United States had military support from the United Kingdom, Australia, and its Commonwealth allies across the planet, the Japanese had effectively seized all American and British territories across the Pacific Ocean and East Asia. It was not until the summer of 1942 where the Allies would finally claim a definitive victory against the Japanese in the Pacific. Although the Battle of the Coral Sea in May was considered a victory by both opposing sides, the Americans and the Australians were able to – for the first time in the war – halt and push back the Japanese’s rapid offensive strategy. The following month, the Battle of Midway was an undisputed American victory, which both saw the Japanese’s naval forces sustain significant long-term damage, and also shifted the nature of World War II in the Pacific into an Allied westward offensive. To begin their offensive in the Pacific, the Allies ultimately determined that the British Solomon Islands should be focused on first. The justification was its proximity to the Allied nations of Australia and New Zealand, as well as recently-discovered intelligence that the Japanese were constructing an airfield on the island of Guadalcanal. The airfield was specifically designed by the Japanese to accommodate long-distance bombers, which if completed could attack Australia, New Zealand, and potentially the west coast of the United States. As the plans were being drafted for the Allied offensive in the Pacific, the military and political leaders found themselves at odds with their prior agreement to focus the Allied war effort on Europe first. This not only complicated the transfer of military personnel and equipment to two opposite sides of the world, but also which leaders would conduct the military actions. The leadership dispute was ultimately resolved, as U.S. Army General Douglas MacArthur and U.S. Navy Admiral Chester Nimitz reached an agreement to regulate American military maneuvers in specific parts of the Pacific Ocean and the South Pacific islands. After assembling their landing forces in Fiji, the initial landing forces who would land on Guadalcanal were dispatched on seventy-five battleships and transports. Out of the 16,000 troops sent to Guadalcanal for the initial landings, the majority were newly-graduated United States Marines under the command of Major General Alexander Vandergrift. While a few thousand Marines were split off to invade the neighboring islands of Gavutu and Tanambogo, 11,000 Marines landed on Guadalcanal on the morning of August 7, 1942. The defending Japanese forces were shocked by the bombardments by the U.S. Navy’s battleships, and their forces fled their newly-constructed airfield and reorganized in the surrounding jungles. Now under American control, the Japanese airfield was renamed by the Marines as “Henderson Field,” in remembrance of Major Lofton Henderson, a Marine aviator who was killed in the Battle of Midway. While the U.S. Marines successfully secured Henderson Field, the bulk of the intense fighting that would later define the entire battle was yet to come.
As the Marines made their way inland to Henderson Field, Japanese aircraft attacked the American naval forces on the coast of Guadalcanal and the surrounding islands, destroying a transport and damaging a destroyer. Vice Admiral Frank Fletcher withdrew his forces from the Solomon Islands in response to the increasing attacks, while Rear Admiral Richmond Turner tried to unload as many of his amphibious landing supplies as possible for the Marines on Savo Island. By the time Turner withdrew on August 9, the Marines had less than half of the supplies that they initially arrived on the island with. Vice Admiral Gunichi Mikawa from the Imperial Japanese Navy chose not to attack the withdrawing American ships, which would later prove to be a major strategic error. Meanwhile on Guadalcanal, the Marines encamped at Henderson Field and combined their landed supplies with the captured Japanese resources. Due to the limited resources and tropical illnesses, the Marines were ordered to eat only two meals a day, and many suffered bouts of dysentery. The Japanese deployed more of their forces to Guadalcanal in an attempt to push the landed Allies off of the island, which would stretch into three major land battles fought through the remainder of 1942. On August 21, a force of 917 soldiers from the Imperial Japanese Army landed on Guadalcanal and marched nine miles west to the Marines’ defensive line. The encamped Marines were warned of the Japanese incursion by Sir Jacob Vouza – an indigenous islander who served with the Allied “Coastwatchers” – minutes before the attack. In the ensuing battle, the Marines held their ground and eliminated 789 of the 917 Japanese soldiers. The skirmish – later called the Battle of the Tenaru – was one of the three major ground battles that was fought between the Allies and the Japanese on Guadalcanal. Although the Japanese underestimated the number of Allied forces that landed on Guadalcanal, they sought to push them out by sending more supplies and ground forces via nightly naval convoys, nicknamed the “Tokyo Express” by the Americans. The 35th Infantry Brigade of the Imperial Japanese Army was part of the “Tokyo Express,” as they were led by Major General Kiyotake Kawaguchi to overwhelm the Americans on Guadalcanal. This led to the Battle of Edson’s Ridge, an intense two-day firefight between the U.S. Marines under the command of Major Generals Alexander Vandegrift and Merrit A. Edson. As the fighting stretched through the two days and nights, the fierce direct fighting that the Japanese forces engaged in – as well as the emerging challenges of jungle warfare – almost had the Marines lose their defensive positions. Although the Marines on the ground were dangerously low on ammunition, the close leadership of Vandegrift and Edson, as well as the advent of air support and reinforcements by other Marines on the island, managed to secure an American victory on September 14. Edson’s successful command of his Marines in the battle would eventually earn him the Medal of Honor, the highest military decoration in the U.S. Armed Forces, and has since cemented him as a highly-venerated figure in the Marine Corps. News of the American victory in the battle raised major concerns among Japan’s military leadership. The increasing casualties and depleting resources for the fighting on Guadalcanal prompted the Japanese to withdraw their forces from their major offensive on New Guinea, making it far easier for the British and Commonwealth armies to defend their positions.
In a final attempt to force the Allies out of Guadalcanal, Lieutenant General Harukichi Hyakutake led the Japanese 17th Army against the American forces in the Battle for Henderson Field. From October 23 to the 26, Major Generals Vandegrift and William Rupertus led the 1st Marine Division in defense of the Lunga perimeter by the Matanikau River. The intense close-proximity fighting that defined the fighting on Guadalcanal had reached its peak, as waves of charging Japanese infantry clashed with American machine guns, mortars, and barbed wire. On the night of October 24, a machine gun section under the command of Marine Sergeant John Basilone – who had single-handedly retrieved ammunition for the machine gun emplacements through the intense crossfire – successfully repelled and nearly wiped out an entire Company of Japanese infantry. In the early morning hours of October 26, another machine gun section under the command of Marine Sergeant Mitchell Paige – who had single-handedly repelled a regiment of Japanese infantry and led a successful bayonet charge – fought off the majority of the Japanese infantry attacking a crucial ridge near Henderson Field. The Battle for Henderson Field had ended in another American victory, with the Japanese forces suffering a more catastrophic loss of personnel than in all the previous land skirmishes combined. After another American victory at sea during the Naval Battle of Guadalcanal in November 1942, the Japanese abandoned their further plans to take the island and evacuated the majority of their remaining forces by February the following year. For their courageous actions in the battle, both Sergeants John Basilone and Mitchell Paige earned the Medal of Honor. The Marines on Guadalcanal were gradually relieved of their duties on the island as 1942 came to an end, as new forces from the U.S. Army’s 25th Infantry Division and the American Division would track down the remaining Japanese forces well into Spring 1943. In the long-term context of World War II, Operation Watchtower has since been considered by historians the definitive turning point in the Allied war effort against the Japanese in the Pacific Theater of Operations. The Japanese were forced to fight on the defensive in the wake of increased Allied advances across the ocean, and the intense fighting on the island reaffirmed public confidence in the United States having a chance to win the war. The hard-fought victory on Guadalcanal gave way to the “island-hopping” campaign, where the Allies would gradually fight their way through the South Pacific, intensifying as they approached the Japanese archipelago by the war’s end in 1945.
Written by Nicholas J. Dilley, Ronald Reagan Presidential Library & Museum