U.S. legislator and the first chairman of the House Committee on Un-American Activities. Largely through Dies' efforts, the House Committee on Un-American Activities was created in May 1938. Dies won praise for the investigation in 1938 of the German-American bunds (associations), regarded as pro-Nazi.
Dies Martin attended Wesley College and the University of Texas. In 1920 he gained a law degree from the National University of Washington, D.C.
Dies Martin practiced law in Texas until he was elected as a Democrat to the U.S. House of Representatives in 1930. As a member of the powerful House Rules Committee he supported New Deal measures during President Franklin D. Roosevelt's first term in office. During Roosevelt's second term, however, Dies followed the lead of his fellow Texan, Vice-President John N. Garner, and opposed the proposed reorganization of the U.S. Supreme Court and other Roosevelt proposals. Declining to seek reelection in 1944, Dies returned to Texas to practice law. He again served in Congress from 1953 to 1959 before again returning to private law practice.