Question: After WWII, when did the US leave the nation it defeated at the Battle of Guadalcanal?

Knowledge 1: Guadalcanal campaign
Surprised by the Allied offensive, the Japanese made several attempts between August and November to retake Henderson Field. Three major land battles, seven large naval battles (five nighttime surface actions and two carrier battles), and almost daily aerial battles culminated in the decisive Naval Battle of Guadalcanal in early November, with the defeat of the last Japanese attempt to bombard Henderson Field from the sea and to land with enough troops to retake it. In December, the Japanese abandoned their efforts to retake Guadalcanal, and evacuated their remaining forces by 7 February 1943, in the face of an offensive by the U.S. Army's XIV Corps. [SEP] Knowledge 2: Occupation of Japan
The Allied occupation of Japan at the end of World War II was led by General Douglas MacArthur, the Supreme Commander of the Allied Powers, with support from the British Commonwealth. Unlike in the occupation of Germany, the Soviet Union was allowed little to no influence over Japan. This foreign presence marks the only time in Japan's history that it has been occupied by a foreign power. The country became a parliamentary democracy that recalled ``New Deal ''priorities of the 1930s by Roosevelt. The occupation, codenamed Operation Blacklist, was ended by the San Francisco Peace Treaty, signed on September 8, 1951, and effective from April 28, 1952, after which Japan's sovereignty -- with the exception, until 1972, of the Ryukyu Islands -- was fully restored.
Knowledge 1: Naval Battle of Guadalcanal
Naval Battle of Guadalcanal Part of the Pacific Theater of World War II Smoke rises from two Japanese aircraft shot down off Guadalcanal on 12 November 1942. Photographed from USS President Adams; ship at right is USS Betelgeuse. Date 12 -- 15 November 1942 Location Guadalcanal, Solomon Islands Result Strategic American victory Belligerents United States Japan Commanders and leaders William Halsey, Jr. Daniel Callaghan † Norman Scott † Willis A. Lee Isoroku Yamamoto Hiroaki Abe Nobutake Kondō Raizo Tanaka Strength 1 carrier 2 battleships 2 heavy cruisers 3 light cruisers 12 destroyers 2 battleships 6 heavy cruisers 4 light cruisers 16 destroyers 11 transports Casualties and losses First phase (13 Nov): 2 light cruisers 4 destroyers Second phase (14 / 15 Nov): 3 destroyers Plus (13 -- 15 Nov): 36 aircraft for a total of 1,732 killed First phase: 1 battleship 1 heavy cruiser 2 destroyers 7 transports Second phase: 1 battleship 1 destroyer 4 transports (beached first) Plus: 64 aircraft for a total of 1,900 killed (exclusive of transport losses) [SEP] Knowledge 2: Occupation of Japan
The Allied occupation of Japan at the end of World War II was led by General Douglas MacArthur, the Supreme Commander of the Allied Powers, with support from the British Commonwealth. Unlike in the occupation of Germany, the Soviet Union was allowed little to no influence over Japan. This foreign presence marks the only time in Japan's history that it has been occupied by a foreign power. The country became a parliamentary democracy that recalled ``New Deal ''priorities of the 1930s by Roosevelt. The occupation, codenamed Operation Blacklist, was ended by the San Francisco Peace Treaty, signed on September 8, 1951, and effective from April 28, 1952, after which Japan's sovereignty -- with the exception, until 1972, of the Ryukyu Islands -- was fully restored.
Knowledge 1: Guadalcanal campaign
Surprised by the Allied offensive, the Japanese made several attempts between August and November to retake Henderson Field. Three major land battles, seven large naval battles (five nighttime surface actions and two carrier battles), and almost daily aerial battles culminated in the decisive Naval Battle of Guadalcanal in early November, with the defeat of the last Japanese attempt to bombard Henderson Field from the sea and to land with enough troops to retake it. In December, the Japanese abandoned their efforts to retake Guadalcanal, and evacuated their remaining forces by 7 February 1943, in the face of an offensive by the U.S. Army's XIV Corps. [SEP] Knowledge 2: Roman Republic
The Romans held off Hannibal in three battles, but then Hannibal smashed a succession of Roman consular armies. By this time Hannibal's brother Hasdrubal Barca sought to cross the Alps into Italy and join his brother with a second army. Hasdrubal managed to break through into Italy only to be defeated decisively on the Metaurus River. Unable to defeat Hannibal on Italian soil, the Romans boldly sent an army to Africa under Scipio Africanus to threaten the Carthaginian capital. Hannibal was recalled to Africa, and defeated at the Battle of Zama.

Answer: April 28, 1952