The government of the United States is divided into three branches. The Legislative Branch writes the laws the people need to follow. Congress is at the head of the Legislative Branch. The Executive Branch carries out the laws. The President is the head of the Executive Branch. The Judicial Branch makes sure that the laws follow the guidelines written in the Constitution. The Supreme Court is the head of the Judicial Branch.
The Supreme Court is made up of nine justices or judges. One of these judges is the leader. He is called the Chief Justice. For many years the Supreme Court was referred to as the "nine old men." That is because for years the justices were all men. There was no rule saying that they should all be men. That's just the way things happened.
This tradition changed for good on July 7, 1981. President Ronald Reagan announced on that day that Sandra Day O'Conner of Phoenix, Arizona, was his nominee to take the place of Justice Potter Stewart who had decided to retire. Who was this person breaking a tradition of almost 200 years? Few people outside of Arizona had ever heard of Sandra Day O'Conner.