Sandra Day O'Connor was the first woman to serve on the U.S. Supreme Court, appointed by President Ronald Reagan in 1981. Her appointment marked a significant milestone in American history, as she broke gender barriers in the judicial system. O'Connor became known for her pragmatic approach to law and often served as a swing vote on contentious issues, influencing critical decisions on topics such as abortion, affirmative action, and federalism. Her tenure on the Court lasted until 2006, and she has since been an advocate for women in law and public service, inspiring future generations of female leaders.