Former Supreme Court Justice Sandra Day O'Connor says she has 'beginning stages of dementia'

O’Connor, 88, was nominated by President Ronald Reagan and took her seat on the court in 1981.

“As a young cowgirl from the Arizona desert, I never could have imagined that one day I would become the first woman justice on the U.S. Supreme Court,” O’Connor wrote Tuesday.

She announced her retirement in 2005 to care for her husband, who had Alzheimer's disease, according to The New York Times and The Washington Post.

“Not long after I retired from the Supreme Court twelve years ago, I made a commitment to myself, my family, and my country that I would use whatever years I had left to advance civic learning and engagement,” O’Connor wrote. She said she started the nonprofit group iCivics, which aims to educate young people about civics and to encourage them to become active citizens, with that goal in mind.

“I can no longer help lead this cause, due to my physical condition,” she wrote. “I hope that private citizens, counties, states, and the federal government will work together to create and fund a nationwide civics education initiative. Many wonderful people already are working towards this goal, but they need real help and public commitment.”

Related: 5 things you need to know about Alzheimer’s disease

In a statement, Chief Supreme Court Justice John Roberts said he was saddened to learn of O’Connor’s diagnosis and that he was not surprised to see she used the news to put out a call to action.

“She broke down barriers for women in the legal profession to the betterment of that profession and the country as a whole,” Roberts said. “She serves as a role model not only for girls and women, but for all those committed to equal justice under law. Although she has announced that she is withdrawing from public life, no illness or condition can take away the inspiration she provides for those who will follow the many paths she has blazed.”

The Associated Press contributed to this report.