Final answer:
The Battle of Midway was a decisive American naval victory in June 1942 that marked a turning point in the Pacific Theater of World War II, halting Japan's expansion and resulting in significant Japanese losses.
Step-by-step explanation:
The Battle of Midway: A Pivotal Victory in WWII
The major battle of World War II that marked a victory for the American Navy and became a significant turning point in the Pacific was the Battle of Midway.
In June 1942, this battle decisively halted Japan's advance across the Pacific. The Japanese forces suffered substantial losses, with four aircraft carriers sunk and a heavy cruiser damaged, causing a permanent setback to the Japanese navy and shifting the balance of power in favor of the Allies.
Forewarned by code-breakers, the US Navy was prepared for the onslaught and despite having fewer resources, managed to repel the attack with much smaller losses, losing only one carrier themselves.
The success at Midway enabled the Allies to start a strategic campaign known as 'island-hopping', gradually moving closer to the Japanese mainland.