His political career began in the House of Representatives in 1907, in which he served for 22 years. While a representative, he fought for low tariffs, and authored the first Federal Income Tax Bill in 1913 (as well as a revision of that bill in 1916) and the Federal and State Inheritance Tax Law in 1916. He left the House for the Senate in 1931, only to be named Secretary of State in FDR's first administration in 1933. His policies encouraged trade and helped to lower tariffs, and his cautionary approach to the developments in Eastern Asia in the 1930s helped prepare the U.S. government for the war with Japan. In his role as Secretary of State, he was integrally involved in the unsuccessful attempt at a peaceful diplomatic resolution with the Empire of Japan in 1940-41; assessments of Hull's efforts range widely among historians, from lauding his work as strong and necessary to deriding it as overly aggressive and war-inciting.
Hull is most noted for being one of the conceivers and most ardent supporters of the United Nations. He was the main figure pushing the State Department to write the "Charter of the United Nations", which it accomplished by mid-1943. Hull resigned the position of Secretary of State in November 1944 because of failing health--Roosevelt said upon Hull's departure that he was "the one person in all the world who has done this most to make this great plan for peace [the United Nations] an effective fact". Hull was honored with the Nobel Peace Prize in 1945 in recognition of his efforts for peace and understanding in the Western Hemisphere, his many international trade agreements, and his work to establish the United Nations.