The front page of the Deseret News on July 21, 1944, as the invasion of Guam began in the final year of World War II. World War II had dragged on for five years when U.S. forces began an invasion to retake Guam on July 21, 1944. The first battle of Guam took place Dec. 8-10, 1941. July 21 is celebrated as Guam Liberation Day, the day when Americans came ashore in 1944. Although organized Japanese resistance ended Aug. 10, some 7,500 Japanese soldiers remained in the jungle for some time, and some continued the fight.