Nancy Kassebaum Baker, the first woman elected to the U.S. Senate without previously having a husband serve in Congress, passed away Friday at the age of 94.

Her son, Bill Kassebaum, confirmed to The Associated Press that she died of natural causes, ending a life defined by public service and political courage.

“She loved Kansas,” Bill Kassebaum told the AP. “She loved people from Kansas and representing Kansas for 18 years in the U.S. Senate.”

He described his mother as “an independent-minded Republican who was willing to stand up for what she thought was right, even if that meant going against the party.”

Kassebaum Baker won election to the Senate in 1978 and served three terms before departing office in 1997, building a distinguished record as a moderate Republican.

She was the daughter of former Kansas Gov. Alf Landon, the Republican Party’s unsuccessful 1936 presidential nominee, a heritage that shaped her deep roots in Kansas political life.

Her initial election to the Senate generated immediate national attention, and by the time she announced her retirement, she stood as the only woman chairing a Senate committee.

Kassebaum Baker was known for reaching across party lines, most notably through a landmark 1996 health insurance law that bore her name alongside that of Democratic Massachusetts Sen. Ted Kennedy.

Her political independence sometimes drew sharp criticism from conservatives, particularly when she supported an assault weapons ban backed by President Bill Clinton, which she said generated the angriest mail of her Senate career.

Despite that controversy, she remained remarkably popular at home, winning re-election in Kansas with 76% of the vote in 1984 and 74% in 1990.

In 1996, shortly before leaving the Senate, she married former Republican Sen. Howard Baker of Tennessee, marking the first marriage between a man and woman who had both served in the Senate.

Howard Baker, who served as President Ronald Reagan’s chief of staff and later as U.S. ambassador to Japan under President George W. Bush, died in 2014.

After leaving Congress, Kassebaum Baker continued her public service, including participating in a bipartisan commission on campaign finance reform during the Clinton administration.

In her later years, she grew increasingly distant from the Republican Party’s direction, endorsing Democrats in several Kansas races, including Democratic Gov. Laura Kelly.

She also called for President Donald Trump’s impeachment following the January 6, 2021, attack on the U.S. Capitol, saying at the time: “This just has gone too far.”

Despite decades spent at the highest levels of national politics, Kassebaum Baker never lost her connection to her home state, once reflecting: “All I can say is, I will miss the Kansas prairie.”