A firm supporter of American intervention in World War II, in 1940 Stevenson headed the Chicago chapter of the Committee to Defend America by Aiding the Allies. In 1941 he joined the Navy Department, remaining there until 1944. Shortly afterward, he joined the State Department as a special assistant to the secretary of state, where he stayed until 1947, serving on the American team at the 1945 San Francisco conference that created the UN and attending several UN General Assemblies.
Returning to Illinois, in 1948 Stevenson was elected governor on the Democratic ticket. As governor, he launched an activist and progressive social reform program and attempted to eradicate corruption. An outspoken opponent of McCarthyism, Stevenson quickly won national recognition as a remarkably eloquent rising political star. He was drafted on the third ballot at the Democratic National Convention in 1952, an open contest since the incumbent president, Harry S. Truman, damaged by McCarthyism and the Korean War, had chosen not to run again. Despite unstinting liberal enthusiasm for Stevenson, he faced an uphill battle against Dwight D. Eisenhower, the popular Republican candidate. Little divided them on foreign policy. Both were staunch Cold Warriors who implicitly endorsed the Truman administration's containment policy. In practice, Stevenson's position on Korea closely resembled that of Eisenhower, yet Stevenson offered no new initiatives but rather an indefinite continuation of the existing Korean stalemate. In 1952 and again in 1956, Eisenhower defeated Stevenson by wide margins.
In 1961, Stevenson hoped that the new Democratic president, John F. Kennedy, would name him secretary of state, but he instead became ambassador to the UN, a position he held for the rest of his life. Both John and Robert Kennedy regarded Stevenson as overly liberal, weak, and indecisive, so they treated him rather contemptuously. For fear of provoking congressional conservatives and the China Lobby, Stevenson was forbidden to express his personal preference for U.S. recognition of the communist People's Republic of China (PRC). Left ignorant of planning for the April 1961 Bay of Pigs invasion of Cuba, Stevenson at first erroneously informed the UN that his country had played no part in it.
Stevenson's finest hour came during the Cuban Missile Crisis, when he aggressively demanded that the Soviet UN representative confirm whether or not his country had deployed nuclear missiles in Cuba and advised the president to take a relatively moderate line during the crisis. Stevenson died in London on 14 July 1965.
Johnson, Walter, ed. The Papers of Adlai E. Stevenson. 8 vols. Boston: Little, Brown, 1972–1979.; Martin, John Bartlow. Adlai Stevenson and the World: The Life of Adlai E. Stevenson. Garden City, NY: Doubleday, 1977.; McKeever, Porter. Adlai Stevenson: His Life and Legacy. New York: William Morrow, 1989.