Henry Martin Jackson, known as Scoop Jackson (May 31, 1912 – September 1, 1983), was a Democratic United States Senator for Washington State, who was known for his expertise in national security matters. U.S. President Ronald Reagan referred to Jackson as "a wise and revered statesman and one who probably understood the Soviets as well as any American in history."  He unseated Senator Harry P. Cain in the 1952 general election and won five more Senate elections.
He sought the Democratic Party nomination for President in 1972 and 1976 but ran poorly in the primaries. Jackson was known as a staunch liberal on economic and social issues but was a strong anti-communist. Jackson remained a popular U.S. Senator until his death. Then Washington Governor John Spellman appointed his fellow Republican former Governor Daniel Jackson Evans, to fill Jackson's seat. A few weeks later, the appointed Evans won a special election against the Democrat Mike Lowry, a then U.S. Representative. Evans remained in the Senate until January 3, 1989, when he was succeeded by Moderate Republican former Senator Slade Gorton, who held the seat until 2001.
- Warren Magnuson, Jackson's long-term Senate colleague from Washington State