WASHINGTON — A former House Republican of Washington state, Jennifer Dunn, who represented Seattle’s conservative east-side suburbs for six terms in Congress, died yesterday, her family said. She was 66.

Dunn, a favorite of both Bush White Houses, was Washington state’s ranking Republican in Congress when she retired in 2004. She told the Associated Press at the time that she was pursuing a new career and planned to enjoy time with her new husband and baby granddaughter.

She died after developing a blood clot while at her Virginia home, her family said in a statement.

Dunn was known for her work on tax issues, promoting women-owned businesses and sponsoring the Amber Alert bill for locating missing children.

Her son Reagan Dunn, a council member in King County, Wash., called her death “a total shock,” adding: “She gave her whole life giving to other people. She touched a lot of lives and did a lot for her country.”

Dunn’s political career was a series of firsts: first woman to chair the Washington State Republican Party; first freshman woman to win a place in the House Republican leadership team, and the highest ranking Republican woman in the GOP leadership as the vice chairman of the Conference.

Rep. Doc Hastings, also a Republican of Washington, who succeeded Dunn as the state’s senior Republican, called her a friend of 32 years.

“She was kind of a trailblazer in many things,” Mr. Hastings said. Dunn was an influential senior member of the House Republican caucus, serving as a member of the Ways and Means Committee, vice chairwoman of the Homeland Security Committee and a member of the caucus campaign team. She was a frequent spokeswoman for the House, once giving the Republican response to a State of the Union Address by President Clinton. She helped run three Republican national conventions.

“While I never took a pledge on term limits, I do believe that our nation is better served if from time to time we senior members step aside to allow individuals with fresh ideas to challenge the status quo in Congress,” she said when she retired.

Bush praised Dunn on her retirement from Congress, calling her “a superb legislator and a strong leader who has stood for the best of Washington State’s values and who has improved the lives of its people.”

She is survived by her husband, Keith Thomson; sons Bryant Dunn, Reagan Dunn, Angus Thomson, and two grandchildren.