Washington state representative Thomas M. Pelly was elected to the 83rd Congress in 1952, and was re-elected to each succeeding Congress until 1972. He was a Republican member of the United States House of Representatives of the first district. Congressman Pelly reached the seniority level of highest ranking Minority Member of both the Subcommittee on Fish and Wildlife Conservation and the busy House Merchant Marine and Fisheries Committee. Of added importance is the fact that he was a high ranking member of the House Science and Astronautics Committee and served on the Advanced Research and Technology Subcommittee.

Pelly entered politics after an active civic and business career in the Seattle community. He served two terms as President of the Seattle Chamber of Commerce, and in 1950, Pelly was selected as Seattle's First Citizen in recognition of his outstanding civic service. He was a member of the Board of Directors of the Seattle Trust and Savings Bank and the Northern Life Insurance Company.

Congressman Pelly's hard work which won him the admiration of the community also brought him awards in Congress. The National Association of Businessmen presented him with the "Watchdog of the Treasury" award, and he held the distinction of having been chosen as one of five outstanding Members of Congress by the United States Chamber of Commerce in 1965. As the senior Republican Member of the House of Representatives from the Pacific Northwest, Congressman Pelly also served as a member of the Executive Committee of the National Republican Congressional Campaign Committee.

Thomas Pelly retired in 1972, and was succeeded in Congress by Representative Joel Pritchard. Pelly died in 1973.