LOS ANGELES — Democratic Sen. Dianne Feinstein, whose groundbreaking political career shattered gender barriers from San Francisco’s City Hall to the corridors of Capitol Hill, said Tuesday she won’t seek reelection in 2024.

The senator, who turns 90 in June, is the oldest member of Congress and has faced questions in recent years about her cognitive health and memory, though she has defended her effectiveness in representing a state that is home to nearly 40 million people.

Sen. Dianne Feinstein, D-Calif., walks through a Senate corridor after telling her Democratic colleagues on Tuesday that she will not seek reelection. “She’s a legend,” Senate Majority Leader Chuck Schumer later told reporters. “A legend in California as the first woman senator; a legend in this Senate. She was the leader on so many different issues.” J. Scott Applewhite/Associated Press

The announcement came after several prominent California Democrats, including U.S. Reps. Katie Porter and Adam Schiff, already had declared Senate campaigns. With Feinstein a now 30-year veteran of the Senate, there hasn’t been a wide open competition for her seat in decades.

Feinstein plans to remain in Congress through the end of her current term. Speaking to reporters in Washington on Tuesday, she said “there’s times for all things under the sun.”

“I think that will be the right time, towards the end of next year,” she said.

Feinstein is one of the Senate’s few remaining veterans of the so-called Year of the Woman, referring to several women who were elected to the male-dominated chamber during the 1992 election. But even before she moved to Washington, Feinstein was one of the most prominent women in American politics.

She was the first woman to serve as president of the San Francisco Board of Supervisors in the 1970s and the first female mayor of San Francisco. She ascended to that post after the November 1978 assassinations of then-Mayor George Moscone and City Supervisor Harvey Milk by a former supervisor, Dan White. Feinstein found Milk’s body.

In the Senate, she was the first woman to head the Senate Intelligence Committee and the first woman to serve as the Judiciary Committee’s top Democrat. She gained a reputation as a pragmatic centrist who left a mark on political battles over issues ranging from reproductive rights to environmental protection.

Feinstein is particularly closely associated with efforts to broaden gun restrictions. Early in her career, the Senate approved her amendment to ban manufacturing and sale of certain types of assault weapons as part of a crime bill that President Bill Clinton signed into law in 1994. The ban expired 10 years later and was never replaced, but it remained a trademark issue in a career that was molded by gun violence.

“Through force of will, she led the fight to get the assault weapons ban passed. Like so many who have been touched by gun violence, that victory was personal for her,” President Joe Biden said in a statement. “I’ve served with more U.S. senators than just about anyone. I can honestly say that Dianne Feinstein is one of the very best.”

She was also known for reaching out to Republicans to find middle ground. While that may have helped her notch legislative accomplishments in Washington, it chafed some in a Democratic Party that has moved increasingly to the left in recent years.

That frustration was on display during her last reelection campaign in 2018. The California Democratic Party endorsed a liberal rival for the seat over her, with some delegates complaining Feinstein had been in Washington too long and hadn’t stood strong enough for immigrants.

She infuriated liberals in 2020 when she closed out confirmation hearings for Justice Amy Coney Barrett with an embrace of Senate Judiciary Committee Chair Lindsey Graham, a Republican, and a public thanks to him for a job well done.

Liberal advocacy groups that had fiercely opposed Barrett’s nomination to replace the late liberal icon Justice Ruth Bader Ginsburg were furious and called for her to step down from the committee leadership. A month later, she announced she would remain on the Judiciary Committee but step down as the top Democrat.

But such tension was forgotten on Capitol Hill on Tuesday, where Democrats praised Feinstein’s career. At a closed-door lunch of Democratic senators, the lawmakers broke into rounds of applause for Feinstein after Senate Majority Leader Chuck Schumer announced her decision.

“She’s a legend,” Schumer later told reporters. “A legend in California as the first woman senator; a legend in this Senate. She was the leader on so many different issues, including assault weapons, environment, women’s rights, and so much else. She approached everything studiously and carefully.”

At the lunch, Feinstein told her colleagues how hard her husband’s death was and that she would be ready to step away from public life after finishing this term, Sen. Elizabeth Warren, D-Mass., said afterward. Feinstein’s husband, Richard Blum, died last year.

“Senator Feinstein made history,” said Warren. “She changed this country and she was a woman on the front lines in fights, like access to assault weapons, and national security and intelligence.”

Warren added: “Every other woman in public office owes a special debt to Dianne Feinstein.”

In her home state, where Feinstein is the longest-serving U.S. senator, she was lionized for her historic tenure in public service.

Democratic U.S. Rep. Nancy Pelosi, the former House speaker, called her San Francisco neighbor “a titan” of the Senate who, among her accomplishments, steered billions of federal dollars to California for environmental protection. Democratic Gov. Gavin Newsom called Feinstein a mentor and credited her with “blazing a trail for a new generation of female lawmakers.”

Associated Press writers Lisa Mascaro and Stephen Groves in Washington contributed.