Nicholas Katzenbach: US official who helped end segregation

Katzenbach, arms folded, confronts George Wallace at the University of Alabama in Tuscaloosa in 1963 (AP)

Nicholas Katzenbach's career in government was the history of America's turbulent 1960s in miniature.

From the civil rights struggle to the Warren report into the assassination of President Kennedy, from the Cuban missile crisis to the failed efforts to end the Vietnam war, Katzenbach was involved, as adviser, policy-maker or policy implementer – in this latter role never more so than in June 1963 when, as deputy US attorney general, he faced down Alabama's governor George Wallace in a confrontationthat provided one of the enduring images of the fight to bring racial justice to the South.

Already, the year before, in October 1962, Katzenbach had been sent to the University of Mississippi to oversee the admission of James Meredith, its first black student. The atmosphere was incendiary: "Shoot anyone who lays a hand on him," attorney general Robert Kennedy told him, as John F Kennedy despatched federal troops. There were violent clashes, but thanks in large measure to Katzenbach's mixture of determination and restraint, the worst was avoided and Meredith was enrolled.

The following June he was back in the South on a similar mission, this time to force the arch-segregationist Wallace to accept two black students at the University of Alabama. Once again Katzenbach succeeded. "I'm not interested in the show," he declared to the segregationist governor stood at a lectern blocking the university's main entrance, flanked theatrically by police officers, and delivering a tirade against the iniquities of the central government. In the end the two students were admitted and Katzenbach cemented his reputation as a man who could hold his nerve and get things done – as an admiring profile described him, "a courageous egghead".

Both parts of that description were true. Born to a prominent political family in Pennsylvania, he enrolled at Princeton University only to leave and join the air force as a navigator when the Japanese attacked Pearl Harbour. In 1943 Katzenbach's plane was shot down, and he spent two years as a prisoner of war in Italy and Germany. Twice he escaped, twice he was recaptured.

At war's end, he quickly completed his studies at Princeton and took a law degree at Yale where he edited the law review, before attending Balliol College, Oxford, as a Rhodes Scholar. When JFK won the 1960 election Katzenbach, like many of his friends, went to Washington. He was a perfect specimen of "the best and the brightest", a talented young lawyer recruited to the Justice Department by the new attorney general, Robert Kennedy.

Like most of that breed he was idealistic but no ideologue. He was unswerving on basic principle, but with a good lawyer's ability to see where the other side was coming from. Katzenbach's intelligence was matched by his lack of pretension. Stooped and balding, and invariably clad in a crumpled suit, he won RFK's trust because he was reliable, dependable and unflappable. The admiration was mutual: Robert Kennedy, he said decades later, was "the most honest person I ever met. Had he lived, he could have been one of America's greatest presidents."

By 1962, Katzenbach had been named deputy attorney general, not onlythe department's point man on civil rights but a counsellor on other important matters. In 1962 he wrote a brief supporting Kennedy's decision to blockade Cuba during the missile crisis, and helped secure the release of prisoners captured during the 1961 Bay of Pigs fiasco.

Then on 22 November 1963, John F Kennedy was assassinated in Dallas. It was Katzenbach who dictated over the phone to one of Lyndon Johnson's aides the text of the oath of office before the new president was sworn in on Air Force One. Three days later, he sent a memo to the White House urging a full public inquiry into the killing: "The public must be satisfied that [Lee Harvey] Oswald was the assassin; that he did not have confederates who are still at large," Katzenbach wrote.

By the time Robert Kennedy stepped down to campaign for the US Senate, Katzenbach had won Johnson's trust as well for his work on the historic1964 Civil Rights Act. Not only was Katzenbach Kennedy's obvioussuccessor; informally he played a no less vital role on occasion, as emissary between Johnson and RFK, whoseconsuming hatred of each other was a subplot of American government in those years.

In 1966, remarkably, Katzenbach proposed himself not for promotion but demotion – suggesting to Johnson that he leave the job of attorney general, one of the "Big Four" cabinet posts, to take the No 2 job at the State Department, of Under Secretary below Dean Rusk. The reasons were several; a lifelong interest in foreign affairs, a fraying relationship with the immovable J Edgar Hoover at the FBI, and a perhaps naïve belief that his skills could find a negotiated settlement to the Vietnam War, by then starting to engulf Johnson's presidency.

LBJ took him up on the offer, but Katzenbach's spell at State was the least satisfying part of his eight years in government. There proved no way out of the war and in January 1969 he left Washington, in his own words "broke and tired, and feeling I'd been something of a failure at the State Department." Afterwards Katzenbach became general counsel at IBM, and retained a keen interest in Democratic politics to the end of his life. In 2008 he published a well-received memoir, Some of It Was Fun: Working with RFK and LBJ. Fun or not, almost all of it was history.

Nicholas deBelleville Katzenbach, lawyer and US government official: born Philadelphia 17 January 1922; US deputy attorney general 1962-65, attorney general 1965-66; Under Secretary of State 1966-69; married 1946 Lydia Phelps Stokes (two sons, two daughters); died Skillman, New Jersey 8 May 2012.