Sandra Day O’Connor, the first woman to serve on the US Supreme Court, has died at the age of 93.
She was appointed by Republican ex-president Ronald Reagan in 1981 and retired from America’s highest court in 2006.
Ms O’Connor died in Phoenix of complications related to advanced dementia and a respiratory illness, the court said.
Her nomination and subsequent confirmation by the US Senate ended 191 years of male exclusivity on the bench.
Chief Justice John Roberts said Ms O’Connor “blazed a historic trail as our nation’s first female justice”.
“She met that challenge with undaunted determination, indisputable ability, and engaging candor,” he said.
“We at the Supreme Court mourn the loss of a beloved colleague, a fiercely independent defender of the rule of law, and an eloquent advocate for civics education.”
At a White House ceremony in 2009, Democrat former president Barack Obama presented her with the medal of freedom, the highest civilian award a president can give.
A native of Arizona who grew up on her family’s sprawling ranch, Ms O’Connor wasted little time building a reputation as a hard worker who wielded considerable political clout on the nine-member court.
She was known as an unwavering voice of moderate conservatism on America’s top legal body.
Her influence and legal thinking as a Supreme Court justice were most closely scrutinized when it came to the court’s rulings on abortion, arguably the most divisive issue it has faced.
Ms O’Connor balked at letting states outlaw most abortions, refusing in 1989 to join four other justices who were ready to reverse the landmark 1973 Roe v Wade decision that said women have a constitutional right to abortion.