As I noted here, regarding retiring Supreme Court Justice John Paul Stevens and his predecessor, and here, regarding Supreme Court justices generally, people tend to stay in that job for a long time. Unlike most presidential appointees, they are not shuttled out of office with every change of administration.
But longevity in the seat Stevens is vacating has been exceptional. Just coincidence, I suppose, but interesting to a trivia buff like me.
The third-to-last justice in that seat was Louis Brandeis, who was appointed by Woodrow Wilson in 1916. (As an aside, Brandeis was the first Jewish justice, which ties into my discussion of identity politics and the Court, earlier today, on my other blog.) A short-timer by the standards of his two successors, Brandeis was on the Court for almost 23 years.
Brandeis's successor, William O. Douglas, appointed by Franklin Roosevelt, set a record, by serving as an associate justice from 1939 to 1975. After suffering a stroke, Douglas reluctantly agreed to retire from the Court. Stevens has held the seat since being appointed by Gerald Ford in 1975.
The seat that is the second most longevity-prone, by that measure, is that of Anthony Kennedy (Hugo Black 1937-1971, Lewis Powell 1971-1987, and Kennedy since 1988).
The seat with the most turnover is Stephen Breyer's. Still, not much turnover; three justices since 1965: Abe Fortas 1965-1969, Harry Blackmun 1970-1994, and Breyer since 1994. Breyer has one longevity record, which I described here.