Question: "What, in the article, first happened during the 52nd year of the 20th century?"  Context: "In 1952, the United States elected a new president, and on 29 November 1952, the president-elect, Dwight D. Eisenhower, went to Korea to learn what might end the Korean War. With the United Nations' acceptance of India's proposed Korean War armistice, the KPA, the PVA, and the UN Command ceased fire with the battle line approximately at the 38th parallel. Upon agreeing to the armistice, the belligerents established the Korean Demilitarized Zone (DMZ), which has since been patrolled by the KPA and ROKA, United States, and Joint UN Commands."  Answer:
Answer:
the United States elected a new president