John Nolan Jr., a longtime partner at Steptoe & Johnson who helped negotiate the Bay of Pigs prisoners' release, has died of pneumonia.

Steptoe & Johnson chair emeritus Roger Warin confirmed the passing of Nolan, whose death at 90 on Nov. 18 at his home in Bethesda, Maryland, was noted this week by The Washington Post. Nolan, a former senior partner at Steptoe & Johnson, once served as an assistant to U.S. Attorney General Robert Kennedy.

“For those of us who had the pleasure of knowing and loving [Nolan], he was the absolute embodiment of what it means to be [a] superb lawyer and human being,” Warin wrote in an email to the firm about Nolan.

Nolan's legal career spanned nearly six decades and intersected with some of the most important moments in American history. After his graduation from the U.S. Naval Academy in 1950, Nolan was commissioned as a second lieutenant in the U.S. Marine Corps and was sent almost immediately to fight on the frontlines in the Korean War, where he was awarded the Bronze Star, the Silver Star and Purple Heart for his service.

Following the war, an experience he chronicled in a 2006 memoir called “The Run-Up to the Punch Bowl,” Nolan was assigned to work at the Navy Yard in Washington, D.C. In 1952, he started taking night classes at the Georgetown University Law Center. When Nolan was decommissioned two years later, he enrolled full-time and graduated in 1955.

Following a clerkship with U.S. Supreme Court Associate Justice Tom Clark, Nolan joined Steptoe & Johnson in 1956. At the time, the firm only had about 20 lawyers. Despite several leaves of absence throughout his tenure, Nolan remained at Steptoe & Johnson throughout his 50-plus years of practice. (In 1980, the firm split into two separate shops that currently use the same name.)

One such leave of absence was in 1960, when Nolan left to work on the presidential campaign of John F. Kennedy. Nolan would subsequently leave Steptoe & Johnson to work for the respective 1964 and 1968 senatorial and presidential campaigns of Robert Kennedy.

In 1962, Nolan was approached by the U.S. Department of Justice, then led by Kennedy and assistant U.S. attorney general Louis Oberdorfer, to assist legendary lawyer James Donovan in negotiating the release of 1,113 men captured in the ill-fated Bay of Pigs invasion of 1961. (Donovan, who died at 53 in 1970, was played by Tom Hanks in the 2015 movie “Bridge of Spies.”)

Nolan traveled several times with Donovan to Cuba to meet the country's leader, Communist revolutionary Fidel Castro, to facilitate the release of prisoners held as a result of the failed Bay of Pigs invasion. In 1967, Nolan gave an oral history interview for the John F. Kennedy Presidential Museum in Boston where he discussed the project, including his interactions with Castro, who he described as “always reasonable, always easy to deal with.”

Ultimately, Cuba agreed to release the prisoners in December 1962 for $53 million in food and medicine amassed through donations and corporate sponsorships. But those negotiations would not be the last time that Nolan would meet with the longtime Cuban dictator.

In a 2003 interview with the Washington Lawyer following his selection as one of its “Legends in the Law,” Nolan recounted that he spent two full days with Castro in 2001, on the 40th anniversary of the Bay of Pigs. Prior to that, Nolan had been gifted a box of Cohiba cigars by Castro via his son-in-law.

In 1963, Nolan took a job as assistant to Kennedy, spending much of his time in the summer of that year in the Deep South by taking part in civil rights efforts organized by the Justice Department. But Nolan's legal career wasn't completely confined to the political arena.

He specialized in environmental law and litigating on behalf of whistleblowing federal employees, including A. Ernest Fitzgerald, who sued President Richard Nixon following his dismissal from the U.S. Air Force.

In his email to Steptoe & Johnson staffers, Warin expressed his sorrow at Nolan's death, but challenged the firm to maintain the high standards set by one of its former leaders and trailblazers.

“Many of us came to Steptoe or stayed at Steptoe because of John Nolan,” Warin said. “We will not see his likes again, but hopefully we can continue the standards he set.”