What kind of work experience do you need to be appointed to the US Supreme Court?

Next week, President Obama is expected to announce who he intends to appoint to the Supreme Court seat left vacant by the death of Antonin Scalia. NPR reported that the President had begun to meet with potential appointees this week. Among the top candidates being interviewed are circuit judges Merrick Garland, Sri Srinivasan, Paul Watford, and Jane Kelly, as well as District Judge Ketanji Brown Jackson. All of these candidates seem fairly conventional: like nine of the last ten justices to join the Supreme Court, they are all federal judges with degrees from respected law schools and little work experience outside practicing and teaching law.

But it is interesting to note that the the résumés of Supreme Court justices were not always so predictable. In fact, the majority of Supreme Court Justices never even earned a law degree, as they entered the profession before the advent of law school. But it's not just education that sets previous justices apart from today's justices: Supreme Court Justices used to have a much wider range of work experience than today's justices. For example, many Supreme Court Justices made their careers in politics, serving as legislators and governors, and holding cabinet positions in the federal government.

Legislators

During the 19th century, it was common for justices to be former legislators. In fact, there was even a period of over ten years from 1826 to 1837 where every single justice on the court had prior legislative experience. Of the first 87 justices to join the Supreme Court, 51 (59%) had previously served as either a state or federal legislator. Since then, just one of 25 justices has had any legislative experience at all: Sandra Day O'Connor served in the Arizona State Senate from 1969 to 1975. The court has been without any legislative experience since O'Connor's retirement in 2006.

Judges

Although it might seem intuitive that a Supreme Court Justice should have prior experience as a judge, nearly 36% of all justices had not served as judges before joinng the court. The most recent example of this is the newest addition to the court, Elena Kagan. In fact, the only period in the history of the court in which all of the justices had prior judicial experience was between the death of William Rehnquist in 2005 and Kagan's appointment on 2010.

In contrast to this period, the 1930s and 1940s saw a relative lack of judicial experience on the court. The low point occurred in 1939, when the only justice with any judicial experience at all was former US Senator Hugo Black, who had spent just 18 months in his twenties working part-time as a police court magistrate in Birmingham, Alabama.

Law School

It became common for justices to hold law degrees as law school gradually became the path by which one entered the law profession. Stanley Forman Reed was the last justice to serve without holding a law degree when he retired in 1957. The last justice appointed to the court without a law degree was James F. Byrnes in 1941, although many mistakenly give this distinction to Robert H. Jackson. Jackson graduated from Albany Law School in 1912, but was given a graduate certificate instead of a law degree due to his being under the age of 21 at the time. But on July 5, 1941, six days before he began his service on the Supreme Court, Albany Law School awarded him the degree he had earned 29 years earlier.

What is also interesting is the increasing representation of Ivy League law schools on the court in recent years. The past ten justices to join the court have all held law degrees from either Harvard, Yale, or Columbia. Two of the top contenders for the current vacancy would break this streak: Srinivasan attended Stanford Law School, and Watford attended UCLA. Sandra Day O'Connor (Stanford) is that last justice to be appointed (1981) without an Ivy League degree, while John Paul Stevens was the most recent justice to serve on the court without an Ivy League degree at the time of his retirement in 2010.

Putting it all together

Below is a summary of the work experience of all 112 justices Supreme Court prior to serving, as well as the work experience of the five top contenders for the current vacant seat (as reported by NPR):
This historical picture of the prior work experience of Supreme Court justices emphasizes that appointing justices with prestigious educational backgrounds and relatively narrow work experience is actually a recent trend. The practice of appointing former legislators, cabinet members, and governors seems to be all but over.