The general narrative of World War II credits the Marines and Navy for the victory in the Pacific and the Army and U.S. Army Air Corps for victory in Europe. In reality, there are actually a few Marine veterans of fighting in Europe and a massive number of Army veterans who fought in the Pacific.
Here are six times that U.S. soldiers took the fight to the Japanese and and laid waste.
1. Battle of Guadalcanal
Yes, that Battle of Guadalcanal. In fact, Army forces on the island actually outnumbered Marine forces. Each branch had two divisions on the ground, but the Army had an additional regiment. The 1st Marine Division made the initial landings on August 7, 1942, but Army troops were pouring onto the island by October.
It was Army troops who first received the "Banzai" attacks against Henderson Field in late October, holding the Japanese back despite armor, artillery, air, and naval support pitted against the U.S. troops. On November 4, the soldiers took part in pushing 1,500 Japanese troops against the sea.
In December, the 1st Marine Division pulled out, and an Army general took over command on the island. He sent his forces against the Japanese headquarters on Mount Austen and it was Army soldiers who fought from mid-December to January 2 to find and destroy that headquarters. In the following months, it was predominantly Army troops who eradicated Japanese opposition on the island, fighting which resulted in three Army Medals of Honor.
2. Papuan Campaign
As the Battle of Guadalcanal raged, U.S. and Australian Army units led the fight in Papua, New Guinea, against Japanese forces there. As with Guadalcanal, a key strategic objective was the island's airfield, but this time, the Japanese were on the attack and the Allies on defense. Unfortunately for the Japanese, their losses to the U.S. Navy at the Battle of the Coral Sea and Midway forced them to attack overland through treacherous mountain passes.
The combined force pushed Japanese foes back and then went on the offensive, attacking at Milne Bay and across the Japanese lines in late August, forcing them into general retreat on September 4. The Army launched a clearance operation on October 4, resupplying units by air as they pushed deeper into formerly Japanese territory. The final Japanese forces proved stubborn, and the Army was forced to fight desperately to take each bunker.
Finally, from mid-December the mid-January, Allied forces led by U.S. Army units brought in fresh tanks and troops, and they launched an innovative combined-arms campaign to break the Japanese backs. In one section where tanks couldn't operate, two Army infantrymen earned posthumous Medals of Honor for heroism while clearing Japanese positions. The last resistance fell by January 22.
3. Capture of Nadzab, New Guinea
While Australian troops did the bulk of the fighting on New Guinea and western New Britain in 1943, U.S. Army paratroopers were tapped to take a key airfield in the city of Nadzab on September 5, 1943.
This was the first American airborne operation of the Pacific. Army Air Corps bombers strafed the drop zones and dropped fragmentation bombs before the paratroopers jumped into a well-timed smokescreen. From there, the paratroopers fought all day, receiving resupply from the air and assaulting one Japanese position after another.
It worked. Australian forces were able to use the airfield for their own operations the very next day, and it was grown into a major air base that supported Australian operations for the rest of the war.
4. Aleutian Campaign
In June, 1942, Japanese forces took two of the Aleutian Islands that are part of Alaska. While their forces lacked the numbers to truly threaten Alaska proper, they were still a problem as they threatened U.S. cities and raided trade and supply routes.
Army soldiers assaulted the beaches on Attu on May 11, 1943, with air and naval support. Despite desperate Japanese defenses, the island fell in a matter of weeks with nearly every Japanese soldier killed by May 30.
On August 15, the Army launched an even larger landing with Canadian support on the island of Kiska, but the Japanese forces had withdrawn in thick fog before the allies arrived. This Japanese withdrawal opened a northern route to attack towards the Japanese home islands, forcing Japan to send some forces north, away from where soldiers and Marines were killing them on other fronts.
5. Island hopping towards The Philippines
During the island hopping campaign back across the Pacific in 1944, the Army actually played a huge role. The Army almost single-handedly took three beaches simultaneously on April 22 on New Guinea, capturing key airfields there within days. On May 18, they took Wakde Island and its airfield. Nine days later, they hit Biak Island, a fierce fight that continued until August 20 as the Japanese repeatedly reinforced the island.
These island assaults also tied up Japanese naval assets, reducing the pressure on Fleet Admiral Chester Nimitz's forces until Japan decided to protect the Marianas at all costs, withdrawing their fleet from fighting Army units ashore and sending it North to the Mariana Islands where the Navy achieved one of its greatest victories at the Battle of the Philippine Sea.
6. Recapturing The Philippines
On October 20, 1944, the Army landed four divisions at once in an effort to retake Leyte, one of the major islands in the Philippines. The Army's efforts were mostly aimed at retaking the Philippines, but it was hoped that, as the Army put pressure on Imperial Japanese land forces, it would force the Japanese Navy into another decisive engagement which Nimitz would, hopefully, win.
What resulted was a fierce land and sea battle October 23 to 26, during which Army forces were fighting bitterly for every yard of ground with limited naval support as the fleets fought each other tooth and nail. It was touch and go for a bit, but the U.S. was eventually victorious on land and at sea, liberating the Philippines and effectively eradicating the bulk of remaining Japanese naval forces.
After this large offensive, the Army took part in the capture of the Ryukyu Islands, including Okinawa, but it was predominantly a Marine show. The Army was slated for a huge role during the invasion of the Japanese home islands, but the surrender of Japan following the dropping of two atomic bombs and the entrance of Russia into the Pacific Theater ended the war and the necessity of another amphibious assault.