American success in the Battles of the Coral Sea and Midway did not bring Japanese ambitions in Oceania to an end.  Beginning in July, American and Australian forces engaged in fierce battle with the Japanese for control of New Guinea.

In August, however, the focus of these battles shifted to Guadalcanal, the largest of the Solomon Islands.  American intelligence reported that the Japanese were building an airfield there—if completed, Japanese places could easily reach Australia and other critical military installations in Oceania such as Espiritu Santo. 

It looked as if it was going to be an easy operation.  On 7 August, American forces landed on Guadalcanal, subdued the small Japanese force, and seized the airfield.  But this initial success was deceptive.  The Japanese could no more allow an American airfield in the Solomons than the Americans could tolerate a Japanese base.  Therefore, the Japanese began to re-deeploy forces on Guadalcanal.  Fierce naval battles ensued as both sides tried to strengthen their forces in the following months.  By mid October, both armies had deployed close to 25,000 men.

The prize pursued by both armies was the now completed airfield under American control. Named Henderson Field, after a flier killed at Midway, the airstrip withstood shelling from Japanese ships, air raids from enemy aircraft, and a major land assault in late October.

The more concerted attempt to recapture the field, however, came in November. While Japanese destroyers shelled the field, transports attempted to land an additional 13,000 solders. They eventually landed 4000, but in just two days, American guns took out two battle ships, several destroyers, and a half dozen transport ships.  More important, during these battles the Americans strengthened their defenses over their transport and supply lines.  By January, American forces approached 60,000, badly outnumbering the Japanese on the island.

With a now decisive manpower advantage, American forces set out to drive the Japanese from Guadalcanal.  It would take more than a month; and 7100 American ground, sea, and air personnel would die in the process.  But by 9 February, the last Japanese soldier had been drive from the island.  

The Japanese had paid dearly in their attempt to take Guadalcanal.  More important strategically than their loss of men, they had lost more the 2000 airplanes and dozens of hard-to-replace ships, including two battleships, three heavy cruisers, and fourteen destroyers.  The Americans had also lost a great deal, but in the Pacific, as in the European theater, the Americans’ ability to replace lost machinery was proving decisive.