Courtesy of Prof. John Q. Barrett of St. John's:
On February 13, 1952, Justice Robert H. Jackson celebrated his 60th birthday. Although the Supreme Court was in recess that week, Jackson and other justices were working in the building. Late that Wednesday afternoon, they were invited to Jackson’s chambers (today Justice Clarence Thomas’s chambers) for a small celebration that included a birthday cake. Chief Justice Fred Vinson and Associate Justices Felix Frankfurter, Harold Burton, Tom Clark and Sherman Minton attended, along with Jackson’s secretary Elsie Douglas, his law clerks and other Court employees.
Justice Burton, a scrupulous diarist, later made this little entry about the occasion:
Late in PM Justice Jackson had a birthday party in his chambers – the Chief Justice, + Justices Frankfurter, Clark + Minton + I attended – also his law clerks his law clerk C. George Niebank Jr + the other.
Niebank’s name was uncommon, but he had been clerking for Jackson for over a year and Burton clearly had gotten to know him. “The other,” apparently Jackson’s second law clerk, had joined the Jackson staff only a few weeks earlier following his December 1951 graduation from law school. His name, William Rehnquist, also was not common. I am sure that Burton in time came to know both the name and the young man. Rehnquist served as a Jackson law clerk through early June 1953 and then went into private law practice in Arizona.