The start of World War II for the Americans was the attack on Pearl Harbor. The day after the Japanese attacked Pearl Harbor in Hawaii they attacked and invaded Guam and many other Pacific islands. They wanted control of Guam because it is right in between Japan and the United States. They thought it would be a good refueling station for ships and planes. The Japanese were attempting to take over most of the Pacific, but it didn't go as planned. Then the Americans defended Guam in 1941, but they failed and retreated. Then in July 1944 the Americans came back to the island and successfully took it back from the Japanese. While the Japanese were in control of Guam they changed names, languages, and customs.