John Beard Allen, born in Crawfordsville, Indiana, but later of Walla Walla, Washington, and former territorial governor Watson Carvosso Squire, born in New York but later of Seattle, were elected as Washington's first United States senators.
John Allen and Watson Squire presented their credentials and took the oath to support the Constitution. Two days later, they drew lots to determine their class assignments. Allen drew Class 2, with a term due to expire on March 3, 1893, while Squire drew Class 3, with a term due to expire on March 3, 1891.
The election credentials of John B. Allen were presented at a special session of the Senate, but he was not permitted to take his seat. Governor John H. McGraw had appointed Allen to fill the Senate vacancy caused by the state legislature having adjourned without electing Allen's own successor. At issue was whether a governor could make an appointment to fill a vacancy at the beginning of a Senate term, as opposed to filling a mid‑term vacancy. On August 28, 1893, a closely divided Senate voted, 32 to 29, that Allen was not entitled to the seat. A vacancy remained in this class from March 4, 1893, to January 31, 1895.
Miles Poindexter, born in Memphis but later of Spokane, began the first of two Senate terms. Elected as a Republican, Poindexter joined the Progressive Party in 1913 and was that party's sole sitting senator. Poindexter's third‑party membership was short‑lived. In 1915 he returned to the Republican Party and was reelected to the Senate in 1916.
Wesley Livsey Jones became chairman of the Senate Committee on Commerce (today's Committee on Commerce, Science, and Transportation), serving until 1930. On January 6, 1930, Jones became the chairman of the Senate Committee on Appropriations, a position he held until 1932.
Clarence Cleveland Dill, born in Fredericktown, Ohio, but later of Spokane, became chairman of the Senate Committee on Interstate Commerce (today's Committee on Commerce, Science, and Transportation), serving until 1935.
Warren Grant Magnuson ("Maggie"), originally of Moorhead, Minnesota, but later of Seattle, took his Senate oath of office after resigning his House seat. Magnuson's 36 years of Senate service remain a record for the state.
Henry Martin "Scoop" Jackson of Everett began the first of his six terms in the Senate. Reelected five more times, Jackson died in office on September 1, 1983. Jackson was Washington state's first native‑born U.S. senator and was an unsuccessful candidate for the Democratic Party's nomination for president in 1972 and 1976.
The Senate moved to accept a bronze statue of Marcus Whitman, a pioneer, doctor, and missionary in the Washington Territory, by Avard Fairbanks, for placement in the National Statuary Hall Collection.
Warren G. Magnuson became chairman of the Committee on Interstate and Foreign Commerce and continued to chair the committee in its subsequent incarnations: the Committee on Commerce, 1961‑1977, and the Committee on Commerce, Science, and Transportation, 1977‑1978. With this continuous service, Magnuson achieved the third-longest tenure of a Senate committee chairman, 23 years and 17 days.
Henry M. Jackson became chairman of the Committee on Energy and Natural Resources, serving until 1981. Jackson had chaired the committee under its former name, the Committee on Interior and Insular Affairs, from 1963 to 1977.
Warren G. Magnuson ended 36 years of service in the Senate and is Washington State's longest-serving senator. The state's duo of "Maggie" and "Scoop" Jackson, as they were affectionately called by their colleagues, was one of the most powerful Senate delegations of the 20th century. During their 27 years together they were often referred to as the "Gold Dust Boys," reflecting the numerous federal projects and federal assistance they attained for their constituents.
Thomas Slade Gorton, III, born in Chicago but later of Olympia, received the Golden Gavel Award for presiding over the Senate for at least 100 hours in a single session. During this single term in office as the state's Class 3 senator, Gorton received the Golden Gavel award twice more, on September 17, 1984, and on July 29, 1986.
Senator Henry M. Jackson was awarded a posthumous Presidential Medal of Freedom, given by the president of the United States to honor individuals who have made great contributions to either the United States or the world. To date, 24 senators have received the award. .
Former senator Thomas Slade Gorton, III of Seattle was again elected to the Senate, this time to the Class 1 seat. Reelected in 1994, Gorton received three more Golden Gavel Awards for presiding over the Senate for at least 100 hours in a single session: September 24, 1996, October 8, 1998, and September 12, 2000. Gorton's six gavels are a Senate record.
The Democratic Conference elected Patty Murray of Seattle, who became Washington State's first woman senator in 1993, chairwoman of the Democratic Senatorial Campaign Committee for the 107th Congress (2001‑2003). She became chairman of the campaign committee again in 2011 and served until 2013.
Patty Murray became the first woman to chair the Senate Committee on Veterans' Affairs, a position she held until 2013.
Maria Cantwell of Edmonds became the first woman to chair the Senate Committee on Indian Affairs, a position she held until February 12, 2014. She then chaired the Senate Committee on Small Business and Entrepreneurship until 2015.