There are nine U.S. Supreme Court Justices, which as of 2015 includes John Roberts Jr., Antonin Scalia, Anthony Kennedy, Clarence Thomas and Ruth Bader Ginsburg. The other four justices are Stephen Breyer, Samuel Anthony Alito Jr., Sonia Sotomayor and Elena Kagan.
John Roberts is the Chief Justice of the United States, while the other eight judges are considered associate justices. Roberts was nominated for Chief Justice by former President George W. Bush, and he was officially appointed in September 2005. Justice Scalia is the longest serving member of the Supreme Court, having served since 1986. He was nominated as an assistant justice by President Ronald Reagan. The next longest serving member of the Supreme Court is Justice Kennedy, who was also nominated by President Reagan. Kennedy took his seat two years after Scalia in 1988.
The most recent addition to the Supreme Court is Justice Kagan, who was nominated by President Barack Obama and took her seat in 2010. Justice Sotomayor was also nominated by President Obama, and she took her seat the year prior to Kagan in 2009. Kagan took over the seat that was vacated by the retired Justice John Paul Stevens, while Sotomayor took over the seat vacated by retired Justice David Souter.