Thomson became involved in the
Republican Party. He was
mayor of
Richland Center from 1944 to 1951 and a member of the
Wisconsin State Assembly from 1935 to 1951, and served as Speaker of the Assembly from 1939 to 1945. He served as
Attorney General of Wisconsin from 1951 to 1957. In 1956, he was elected governor of Wisconsin, defeating
William Proxmire; he was defeated for reelection as governor in 1958 by
Gaylord Nelson. In 1960, he was elected to the
United States House of Representatives representing
Wisconsin's 3rd congressional district. He served in the
87th and was reelected to the six succeeding congresses. Thomson voted in favor of the
Civil Rights Act of 1964. He was defeated for
reelection in 1974, losing to
Alvin Baldus. He resigned before the official end of his term, overall serving from January 3, 1961 till December 31, 1974. Thomson was a member of the
Federal Election Commission. Thomson died in
Washington, D.C., and was buried in
Richland Center, Wisconsin. ==References==