It halted Japanese expansion to the East
Context:
In the Battle of the Coral Sea (May, 1942), the American fleet and warplanes defeated a Japanese armada. Australian forces also participated in the battle, but the United States led the effort. It was the first air-sea battle in history, with aircraft carriers and planes from the two sides engaging one another. Both sides suffered damages, but the overall victory was won by the American side. It was the first time the Japanese advance had been checked by the Allies.