General Douglas MacArthur was a prominent American military leader during the 20th century. He played a key role in the Pacific Theater during World War II, leading Allied forces in the fight against Japan. MacArthur is known for his strategic planning and his famous return to the Philippines, where he had vowed, "I shall return" after being forced to leave in 1942. After the war, MacArthur oversaw the occupation of Japan and helped to rebuild the country, implementing democratic reforms. He also served as the Supreme Commander for the Allied Powers in Japan and was involved in the early stages of the Korean War, where he led United Nations forces before being relieved of command in 1951.