The Supreme Court of the United States is the highest ranking judicial body in the United States. Its membership, as set by the Judiciary Act of 1869, consists of the Chief Justice of the United States and eight associate justices, any six of whom would constitute a quorum. Justices are nominated by the President of the United States and appointed after confirmation by the United States Senate. Justices of the Supreme Court have life tenure and receive a salary which is set at $255,500 per year for the chief justice and at $244,400 per year for each associate justice as of 2014.
The current Chief Justice (since September 2005) is John Roberts. The newest Associate justice is Elena Kagan, who became the 112th person to serve on the Court in August, 2010. One seat on the Court has been vacant since the February 13, 2016 death of Associate Justice Antonin Scalia.
The Supreme Court was created in 1789 by Article III of the United States Constitution, which stipulated that the "judicial Power of the United States, shall be vested in one supreme Court" together with any lower courts Congress may establish. Congress organized the Court that year with the passage of the Judiciary Act of 1789. It specified the Court's original and appellate jurisdiction, created thirteen judicial districts, and fixed the number of justices at six (one chief justice and five associate justices).
Since 1789, Congress has occasionally altered the size of the Supreme Court, historically in response to the country's own expansion in size. Membership was decreased in 1801 to five, then increased to seven members in 1807, to nine in 1837, and to ten in 1863. It was then reduced to seven in 1866. In 1869, Congress set the Court's size to nine members, where it has remained since.