Retired Justice Sandra Day O'Connor returned to the Supreme Court Monday to listen to a farewell letter, written by Chief Justice William Rehnquist before he died, praising her tenure as the nation's first woman justice.

"When you came to the court 24 years ago, you faced the same challenges that new members of the institution have always faced. But in addition you faced a challenge that none of them had faced -- you were the first woman justice," Rehnquist wrote in the July 18 letter that was signed "affectionately" by all of the justices.

"Your decision to retire brings a sense of loss to each of us," the former chief justice wrote.

The letter was read by Justice John Paul Stevens, the court's senior member.

As the letter was read, O'Connor sat in a reserved section at the front of the courtroom. Several justices smiled in her direction as they took their seats at the beginning of Monday's session.

Rehnquist, who died in September, also wrote that O'Connor left her "mark on every major field of the court's jurisprudence."

John Roberts, who replaced Rehnquist as chief justice and served briefly with O'Connor, read his own letter thanking O'Connor for her "invaluable guidance and support over the past several months."

In her letter to her former colleagues, O'Connor said she will cherish her work with the justices. "I look back on my 24-plus years here with warm appreciation for all the goodwill each of you has shown to me despite the occasionally contentious nature of our work.

"I can truly say our nation is blessed by having a Supreme Court with such gifted, intelligent and hardworking members," O'Connor wrote. "The process followed here works remarkably well."