Battle of Guadalcanal

On August 7, 1942, the first American offensive in the Pacific during WII, The Battle of Guadalcanal, began with the landing of Marines. From the article:

"Battle of Guadalcanal
The World War II Battle of Guadalcanal was the first major offensive and a decisive victory for the Allies in the Pacific theater. With Japanese troops stationed in this section of the Solomon Islands, U.S. marines launched a surprise attack in August 1942 and took control of an air base under construction. Reinforcements were funneled to the island as a series of land and sea clashes unfolded, and both sides endured heavy losses to their warship contingents. However, the Japanese suffered a far greater toll of casualties, forcing their withdrawal from Guadalcanal by February 1943.

When Japanese troops arrived on Guadalcanal on June 8, 1942, to construct an air base, and then American marines landed two months later to take it away from them, few people outside of the South Pacific had ever heard of that 2,500-square-mile speck of jungle in the Solomon Islands. But the ensuing six-month Guadalcanal campaign proved to be the turning point of the Pacific war.

Strategically, possession of a Guadalcanal air base was important to control of the sea lines of communication between the United States and Australia. Operationally, the Battle of Guadalcanal was notable for the interrelationship of a complex series of engagements on the ground, at sea, and in the air. Tactically, what stood out was the resolve and resourcefulness of the U.S. Marines, whose tenacious defense of the air base dubbed Henderson Field enabled the Americans to secure air superiority.

By the end of the battle on February 9, 1943, the Japanese had lost two-thirds of the 31,400 army troops committed to the island, whereas the U.S. Marines and the U.S. Army had lost less than 2,000 soldiers of about 60,000 deployed. The ship losses on both sides were heavy. But by far the most significant loss for the Japanese was the decimation of their elite group of naval aviators. Japan after Guadalcanal no longer had a realistic hope of withstanding the counteroffensive of an increasingly powerful United States."