Justice Elena Kagan recalled the moment 30 years ago when her boss looked at her "as though I must have lost my mind."

The boss was Justice Thurgood Marshall and the setting was his Supreme Court office, where Kagan was spending a year as a law clerk after graduating from Harvard Law School.

Kagan had just delivered what she deemed a clear and simple explanation for why Marshall should side against a North Dakota girl who lived 16 miles from her school and whose family could not afford the bus service to get her there. The school district wouldn't waive the fee.

The legal giant who argued for the end of segregated schools and the first African-American on the court was not going to cast a vote against a poor school girl.

The story, recounted Tuesday evening in the courtroom where Marshall worked for 24 years, was part of a warm recollection by three judges and a Harvard law professor of their time spent as Supreme Court law clerks for Marshall, whose first term on the court was 50 years ago. Marshall's widow, Cecilia, and sons Thurgood and John were in the audience.

Sarita Kadrmas, the girl who sued, was white, but that was of no consequence in Marshall's thinking, Kagan said. "His basic idea of what he was there to do was ... to ensure that people like Sarita Kadrmas got to school every morning," Kagan said.

Kagan's initial view of the case turned out to be the majority's view in a 5-4 decision written by Justice Sandra Day O'Connor.

Kagan drafted Marshall's dissent and it took several versions "until he felt like I got the right level of passion and disgust," she said.

Marshall was a master storyteller and Judge Douglas Ginsburg, who sits on the federal appeals court in Washington, remembered Marshall's habit of wandering into his clerks' workspace after lunch and spinning tales for 30 to 45 minutes about his days representing black defendants in the Jim Crow South. The stories could be horrific accounts of racial injustice and also quite funny, often at the same time.

Kagan recalled how Marshall judged the fairness of death penalty trials. "I remember once he said to us that when a jury brought back a sentence of life imprisonment, that's when he absolutely knew that the guy was innocent."

All these years later, Kagan said, Marshall continues to influence her. "His voice in my head never went away in terms of trying to figure out what I was doing and why," she said.