Adlai Ewing Stevenson II was born in Los Angeles on February 5, 1900. He was a member of a famous Illinois political family. His grandfather Adlai E. Stevenson I was Vice President of the United States under President Grover Cleveland from 1893–1897. His father, Lewis G. Stevenson, was Secretary of State of Illinois and was considered a strong contender for the Democratic vice-presidential nomination in 1928. Stevenson was raised in the city of Bloomington, Illinois. At the age of twelve Stevenson accidentally killed Ruth Merwin, a 16-year-old friend, while demonstrating drill technique with a rifle, inadvertently left loaded, during a party at the Stevenson home. He was devastated by the accident and rarely referred to it as an adult. However, in 1955 Stevenson heard about a woman whose son had experienced a similar tragedy. He wrote her that she should tell her son that "he must live for two", which Stevenson's friends took to be a reference to the shooting incident.
Stevenson went to boarding school in Connecticut at The Choate School. Upon his graduation from Choate in 1918, he enlisted in the Navy and served at the rank of Seaman Apprentice, but his training was completed too late for him to participate in World War I. He attended Princeton University, and then went to Harvard Law School but failed several classes and withdrew. He returned to Bloomington where he wrote for the family newspaper, The Daily Pantagraph, which was founded by his maternal great grandfather Jesse W. Fell, who had also served as Abraham Lincoln's campaign manager in his 1858 race for the US Senate.
Stevenson decided to finish his law degree at Northwestern University School of Law, and received his law degree in 1926 and passed the Illinois State Bar examination that year. He obtained a position at Cutting, Moore & Sidley, an old and conservative Chicago law firm. In 1928 Stevenson married Ellen Borden, a well-to-do socialite. They had three sons: Adlai Stevenson III, who would become a U.S. Senator; Borden Stevenson, and John Fell Stevenson. In 1935 Adlai and Ellen purchased a 70-acre piece of land along the Des Plaines River near Libertyville, Illinois, a wealthy suburb of Chicago. Although he spent relatively little time there due to his career, Stevenson did consider the farm to be his home, and in the 1950s he was often called "The Man from Libertyville" by the national news media. In 1949 Adlai and Ellen were divorced; Stevenson did not remarry.
In 1948 Stevenson was chosen by Jacob Arvey, the leader of the powerful Chicago Democratic political organization, to be the Democratic candidate in the Illinois gubernatorial race against the incumbent Republican, Dwight H. Green. In a major upset, Stevenson defeated Green by 572,067 votes, a record margin in Illinois gubernatorial elections. As Illinois governor he reorganized the state police by removing political considerations from hiring practices and instituting a merit system for employment and promotion, cracked down on illegal gambling, and improved the state highways. He also vetoed a bill that would have "made it a felony to belong to any subversive group" and would have required "a loyalty oath of public employees and candidates for office." In his public message regarding the veto Stevenson wrote "I know full well this veto will be distorted and misunderstood...I know that to veto this bill in this period of grave anxiety will be unpopular with many. But I must, in good conscience, protest against any unnecessary suppression of our ancient rights as free men...we will win the contest of ideas that afflicts the world not by suppressing those rights, but by their triumph." In 1949, Governor Stevenson testified before the House Committee on Un-American Activities to defend Alger Hiss, a former high ranking State Department official who was accused of being a Soviet spy.
Early in 1952, while Stevenson was still governor of Illinois, President Harry S. Truman decided that he would not seek another term as president. Truman met with Stevenson in Washington and proposed that Stevenson seek the Democratic nomination for president. Truman promised him his support if he did so. Despite his reluctance to run, delegates at the Democratic drafted him, and he accepted the Democratic nomination.
Although Stevenson's eloquent oratory and thoughtful demeanor impressed many intellectuals and members of the nation's academic community, the Republicans and some working-class Democrats ridiculed what they perceived as his indecisive, aristocratic air. During the 1952 campaign, his opponents labeled Stevenson an "egghead", based on his baldness and intellectual air. Stevenson himself made fun of his nickname. In one speech he joked "eggheads of the world unite, you have nothing to lose but your yolks!"
Stevenson did not use television as effectively as his Republican opponent, popular war hero Dwight D. Eisenhower, and was unable to mobilize the New Deal coalition for one last hurrah. In the election, Eisenhower won the popular vote by 55% to 45%. Stevenson lost heavily outside the Solid South. He won only nine states and lost the Electoral College vote 442 to 89.
With Eisenhower headed for another landslide, few Democrats wanted the 1956 nomination. This time Stevenson campaigned more aggressively for the nomination. To Stevenson's dismay, former president Truman endorsed Avreill Harriman, but former first lady Eleanor Roosevelt's supported Stevenson and he once again won the nomination at the 1956 Democratic National Convention in Chicago. Stevenson waged a vigorous presidential campaign, delivering 300 speeches and traveling 55,000 miles. President Eisenhower suffered heart problems, but the economy enjoyed robust health. Stevenson's hopes for victory were dashed when, in October, President Eisenhower's doctors gave him a clean bill of health and the Suez and Hungary crises erupted simultaneously. Stevenson lost his second bid for the Presidency by a landslide, winning only 42% of the popular vote and 73 electoral votes from just seven states.
Despite his two defeats, Stevenson considered a third nomination. Prior to the 1960 Democratic National Convention, Stevenson announced that he was not seeking the Democratic nomination for president, but would accept a draft. Once John F. Kennedy won the nomination, Stevenson campaigned actively for him. Stevenson considered himself as a natural choice for United States Secretary of State but instead Stevenson was appointed United States Ambassador to the United Nations.
His most famous moment came during the Cuban missile crisis when he gave a presentation at an emergency session of the Security Council on October 25, 1962. He forcefully asked Soviet representative Valerian Zorin if his country was installing missiles in Cuba, punctuated with the famous demand "Don't wait for the translation, answer 'yes' or 'no'!" Following Zorin's refusal to answer the abrupt question, Stevenson retorted, "I am prepared to wait for my answer until Hell freezes over." In one of the most memorable moments in U.N. history, Stevenson then showed photographs that proved the existence of missiles in Cuba, just after the Soviet ambassador had implied they did not exist.
After President Kennedy was assassinated Stevenson continued to serve in his position as Ambassador to the UN under the Johnson administration. Stevenson was not a major player on Vietnam issues. He did support Johnson publicly and in private he wanted to start negotiations with North Vietnam through the UN, which Johnson rejected.
While walking in London through Grosvenor Square, Stevenson suffered a heart attack on the afternoon of July 14, 1965, and died later that day of heart failure at St George's Hospital.