In February 1946, Galbraith took a leave of absence from his magazine work for a senior position in the State Department as director of the Office of Economic Security Policy where he was nominally in charge of economic affairs regarding Germany, Japan, Austria, and South Korea. He was distrusted by the senior diplomats so he was relegated to routine work with few opportunities to make policy. Galbraith favored detente with the Soviet Union, along with Secretary of State James F. Byrnes and General Lucius D. Clay, a military governor of the US Zone in Germany from 1947 to 1949, but they were out of step with the containment policy then being developed by George Kennan and favored by the majority of the US major policymakers. After a disconcerting half-year, Galbraith resigned in September 1946 and went back to his magazine writing on economics issues. Later, he immortalized his frustration with "the ways of Foggy Bottom" in a satirical novel, The Triumph (1968). The postwar period also was memorable for Galbraith because of his work, along with Eleanor Roosevelt and Hubert Humphrey, to establish a progressive policy organization Americans for Democratic Action (ADA) in support of the cause of economic and social justice in 1947.  During his time as an adviser to President John F. Kennedy, Galbraith was appointed United States Ambassador to India from 1961 to 1963. His rapport with President Kennedy was such that he regularly bypassed the State Department and sent his diplomatic cables directly to the president. In India, he became a confidant of Prime Minister Jawaharlal Nehru and extensively advised the Indian government on economic matters. In 1966, when he was no longer ambassador, he told the United States Senate that one of the main causes of the 1965 Kashmir war was American military aid to Pakistan.  While in India, he helped establish one of the first computer science departments, at the Indian Institute of Technology in Kanpur, Uttar Pradesh. Even after leaving office, Galbraith remained a friend and supporter of India. Because of his recommendation, First Lady of the United States Jacqueline Bouvier Kennedy undertook her 1962 diplomatic missions in India and Pakistan.  In autumn 1972 Galbraith was an adviser and assistant to Nixon's rival candidate George McGovern in the election campaign for the American presidency. During this time (September 1972) he travelled in to China in his role as president of the American Economic Association (AEA) at the invitation of Mao Zedong's communist government with the economists Leontief and Tobin and in 1973 published an account of his experiences in A China Passage. Galbraith wrote that there was "no serious doubt that China is devising a highly effective economic system," "[d]issidents are brought firmly into line in China, but, one suspects, with great politeness," "Greater Shanghai ... has a better medical service than New York," and considered it not implausible that Chinese industrial and agricultural output was expanding annually at a rate of 10 to 11%.

Answer this question "What did he do after he worked there?" by extracting the answer from the text above.
Galbraith resigned in September 1946 and went back to his magazine writing on economics issues.