In the meantime, U.S. forces were advancing in the Pacific. Although U.S. troops were forced to surrender in the Philippines in early 1942, the Allies rallied in the following months. General James "Jimmy" Doolittle led U.S. army bombers on a raid over Tokyo in April that had little actual military significance, but gave Americans an immense psychological boost. In the Battle of the Coral Sea the following month -- the first naval engagement in history in which all the fighting was done by carrier-based planes -- the Japanese navy incurred such heavy losses that they were forced to give up the idea of striking at Australia. The Battle of Midway in June in the central Pacific Ocean became the turning point for the Allies, resulting in the first major defeat of the Japanese navy, which lost four aircraft carriers, ending the Japanese advance across the central Pacific.
Other battles also contributed to Allied success. Guadalcanal, a decisive U.S. victory in November 1942, marked the first major U.S. offensive action in the Pacific. For most of the next two years, American and Australian troops fought their way northward along a central Pacific island "ladder" capturing the Solomons, the Gilberts, the Marshalls, the Marianas and the Bonin Islands in a series of amphibious assaults.
Source: U.S. Department of State