From the buzz inside San Francisco's Herbst Theatre, you might have guessed the crowd was waiting for a pop star to appear. People began arriving an hour before show time, anxious eyes scouring the room for vacancies among the facility's 916 seats.

It was not until a white-haired, 82-year-old woman walked on stage Monday afternoon and flashed a warm grin that the murmurs stopped and applause shook the room.

Sandra Day O'Connor, the first woman to serve on the U.S. Supreme Court, retired in 2006, but no one has forgotten her place in history. When she accepted Ronald Reagan's nomination in 1981 -- she was confirmed by a 99-0 Senate vote -- she shattered a gender barrier that had spanned 192 years.

Her widely praised time on the bench paved the way for Ruth Bader Ginsburg, Elena Kagan and Sonia Sotomayor, the female justices serving today.

"When I look up and see three women there, it's just astounding," she said. "Look how many years it took to get even one."

O'Connor's appearance before the Commonwealth Club was to address a favorite topic, "The Necessity of Civic Education," and to plug her website, www.icivics.org. She's a tireless advocate for education about how government works and the importance of citizen involvement.

But that's not all she shared. During a question-and-answer session with moderator Mary Bitterman, O'Connor talked about the experiences that shaped her life.

She was raised on an Arizona cattle ranch, the Lazy B, where electricity was a rumor and the nearest town was 35 miles away. She fed chickens, milked cows and prepared meals for cowboys who wrangled cattle. Her father, Harry, demanded accountability, as she learned when she was late delivering lunch one day.

"I explained that I was sorry, that I'd had a flat tire," she said. "My father was livid. He said, 'You should have started earlier.'"

A powerful work ethic helped her earn bachelor's and law degrees at Stanford and endure the frustration of being denied employment at more than three dozen San Francisco law firms. "Not a single one of them would give me an interview," she said. "They said, 'We don't hire women lawyers. We never have.'"

Her launchpad to history was the San Mateo County Attorney's office, where she started out working for free. She later was an Arizona assistant attorney general, state senator and a judge on the State Court of Appeals. The day Reagan called, she rushed home to husband, John, and said, "You won't believe the phone call I got today."

The audience was eager to pepper her with questions.

Did she ever regret a judicial decision? "I'm not that kind of person. I put my effort in at the front end, find out everything I can, make a decision and move on."

What decision was the most difficult? "Does Bush v. Gore ring a bell?"

Does she believe in judicial activism? "I think judges should write narrow opinions that deal with specific issues, not make broad rules that may affect the future."

Was it hard being the first female on the court? "I felt no resentment from my colleagues -- but there was a problem. We didn't have a women's restroom."

There was no need for pop stars at the Herbst on Monday afternoon. The crowd was fully captivated by one of history's pioneers.

Contact Tom Barnidge at tbarnidge@bayareanewsgroup.com.