Last week when President Obama awarded Sandra Day O'Connor with the Presidential Medal of Freedom, he described her as a "pilgrim who has forged a new trail and built a bridge behnid her for all young women to follow."  O'Connor was the first woman appointed to the highest U.S. court.

When she announced in 2005 that she was stepping down from the Supreme Court after 28 years in order to care for her ailing husband, Democratic Senator Ted Kennedy praised her for her service on the nation's highest court. "She was a careful and thoughtful and highly respected member of the court, a wise judge who served the nation and the Constitution well," Senator Kennedy said.  

Sandra Day O'Connor was appointed to the Supreme Court in 1981 by Ronald Reagan, perhaps the most conservative U.S. president in recent history. But she did not always vote with her conservative colleagues. Sometimes she sided with the liberals. She often cast the deciding vote. 

As Nancy Maveety, author of Sandra Day O'Connor: Strategist on the Supreme Court, points out, O'Connor - more often than any of the other eight justices - voted with the majority. "It appears, when we look at certain high profile decisions particularly, that O'Connor controls the court, that the balance of power is in her hands alone," Maveety says. 

That may be something of an exaggeration, but there is no question that Sandra Day O'Connor was influential. Acording to Joan Biskupic, author of Sandra Day O'Connor: How the First Woman on the Supreme Court Became Its Most Influential Justice, lower court judges base their rulings on standards Justice O'Connor set forth in a number of key decisions involving abortion rights, death penalty appeals and the separation of church and state.
"For example, if your local city council wants to put up a nativity scene," Biskupic says, "and someone challenges it as a violation of the separation of church and state, a local judge would look to a rule that Sandra Day O'Connor wrote about what a reasonable observer would believe about this religious display. 

Born in Texas in 1930, Sandra Day O'Connor grew up on a large, isolated cattle ranch in Arizona. "All of my childhood experiences were related to the ranch," O'Connor says. "It's a place that I love very deeply. It's a way of life that I respect. In fact, as a young girl, my ambition in life was to be a cattle rancher, not a lawyer." 

So, with an eye on business, she majored in economics at Stanford University in California, but discovered that she loved law. Although she graduated third in her class from Stanford Law School, she found that private firms in 1952 weren't interested in hiring women attorneys.  "The only offer that I received on graduation from law school was with one major firm in California and they offered me a job as a legal secretary," Justice O'Connor recalls. "I discovered that the opportunity for employment for women lawyers in those days was better in the public sector than in the private." 

So, she became a county attorney in California. She practiced law on her own for a few years in Phoenix, Arizona, where she and her husband later settled, before becoming a full-time mother to three sons.  

In 1969, she was elected to the state legislature as a Republican and eventually became the first woman majority leader of the Arizona senate. Seven years as a state judge followed before Ronald Reagan tapped her for the Supreme Court. 

"She wrote Ronald Reagan a letter shortly after she was sworn in that said: 'A thousand speeches could not have done what your one act of nominating me to the Supreme Court did,'" says biographer Joan Biskupic. "She believed, and I think this is right, it sent the message to a lot of legal quarters that women were up to the job."

Biskupic says O'Connor proved that by not only holding her own with the eight men she joined on the bench, but by gradually becoming the most influential justice on the Supreme Court.

Since stepping down from the Court, O'Connor has spoken out on the state of the American judiciary, and the threats she sees to judicial independence. Concerned by the lack of knowledge among young Americans about how their government works, she created a website to offer fun, interactive civics lessons for students and teachers.

Twenty-eight years after Sandra Day O'Connor broke the gender barrier in the nation's highest courtroom, women now preside over one quarter of the federal and state courts across the nation. And as O'Connor accepted the Medal of Freedom this month from President Barack Obama, the third woman appointed to the U.S. Supreme Court prepared to take her place on the nation's highest bench.