“I was so inspired that I drove six hours to L.A. in a falling-apart Toyota and slept on somebody’s floor,” Ms. Schaaf, now 57, recalled. Decades later, after a career as a lawyer and a political aide, Ms. Schaaf won a seat on the Oakland City Council and, in 2015, became the second woman to serve as the city’s mayor.

Though Ms. Feinstein lost that governor’s race to Mr. Wilson, she turned around to win a special election to fill the Senate vacancy left by his departure from Congress. By then, a new furor consumed the nation over the confirmation hearings of Clarence Thomas for the Supreme Court, during which Anita Hill told the male-dominated Senate Judiciary Committee that Judge Thomas had sexually harassed her when he was her supervisor.

Ms Feinstein and Ms. Boxer campaigned together, “almost as a slate” and often hand-in-hand, Ms. Boxer said, recalling Ms. Feinstein’s generosity as a politician. Ms. Feinstein, who had already run statewide and was widely known for her moderate views and her courage in San Francisco, was far more popular in California than Ms. Boxer, a liberal congresswoman in a state that, in those days, tilted right in statewide races.

“She easily could have said, ‘Barbara, good luck.’ Instead, she said, ‘Barbara, we’re in this together,’” Ms. Boxer recalled.

In what would later be called “The Year of the Woman,” Senator Feinstein was sworn in shortly after the election, two months ahead of Senator Boxer, and California became the first state with two female senators. Ms. Boxer retired from the Senate in 2017 and now lives in Palm Springs. Ms. Feinstein was the longest-serving senator in California history when she died at her Washington, D.C., home.