Contributor(s): Sandra Day O'Connor | Sandra Day O'Connor is an American jurist who was the first female member of the Supreme Court of the United States. Justice O'Connor was appointed an Associate Justice by President Ronald Reagan in 1981, a position she held for 25 years until her retirement in 2006. Viewed as one of the most influential Justices to serve on the modern US Supreme Court, Justice O'Connor became the ""swing opinion"" in the often divided Court on which she sat in the later years of her tenure. Prior to Justice O'Connor's appointment to the Court, she was an elected official and judge in Arizona. Justice O'Connor is Chancellor of The College of William & Mary in Williamsburg, Virginia, and serves on the board of trustees of the National Constitution Center in Philadelphia, Pennsylvania. On August 12, 2009, she was awarded the Presidential Medal of Freedom, the highest civilian honour of the United States, by President Barack Obama. Jeffrey Golden is a visiting professor of Law at LSE.