On June 15, 1944, U.S. Army and U.S. Marine divisions under Admiral Chester W. Nimitz landed on Saipan, beginning a bloody three-week battle. Then, on July 21, Army and Marine units invaded Guam, one hundred miles south of Saipan, and three days later, Marines attacked Tinian Island. Guam fell to the Third Marine, Seventy-seventh Army divisions, and First Marine Brigade on August 10, after a difficult struggle. Admiral Marc Mitscher’s Fast Carrier Task Force (which included six heavy and six light carriers, escorted by fast battleships, cruisers, and destroyers) used bombers to strafe Guam, neutralizing the Japanese airfield.

The first Marines to land on Guam plant a U.S. flag on the beach. (National Archives)

On June 15, 1944, U.S. Army and U.S. Marine divisions under Admiral Chester W. Nimitz landed on Saipan, beginning a bloody three-week battle. Then, on July 21, Army and Marine units invaded Guam, one hundred miles south of Saipan, and three days later, Marines attacked Tinian Island. Guam fell to the Third Marine, Seventy-seventh Army divisions, and First Marine Brigade on August 10, after a difficult struggle. Admiral Marc Mitscher’s Fast Carrier Task Force (which included six heavy and six light carriers, escorted by fast battleships, cruisers, and destroyers) used bombers to strafe Guam, neutralizing the Japanese airfield.

The United States had 1,400 fatalities and 5,600 wounded. The Japanese, led by Jisaburo Ozawa, had 10,000 fatalities, and several hundred more died when they refused to surrender during the mopping-up operations.

The Battle of Guam was an important turning point of the Pacific war because the U.S. seizure of the Marianas placed the U.S. Army Air Force’s B-29 bombers in easy reach of Japanese islands, enabling the United States to fly missions against Japan in late November and destroying Japan’s objective of controlling the Pacific.