WICHITA, Kan. (AP) — As the nation’s oldest sitting federal judge in history, U.S. District Judge Wesley Brown allowed himself few concessions to his advancing age as he insisted on presiding over significant and often complex cases right up until his death at 104.

Brown died Monday night at the Wichita assisted living center where he lived, his law clerk, Nanette Turner Kalcik, said Tuesday.

During his long tenure, the senior judge in Wichita repeatedly tried to explain why he had not yet fully retired from the federal bench.

“As a federal judge, I was appointed for life or good behavior, whichever I lose first,” Brown quipped in a 2011 interview with The Associated Press. How did he plan to leave the post? “Feet first,” Brown said.

He came to work at the federal courthouse every day until about a month ago when his health deteriorated, U.S. District Judge J. Thomas Marten said. Undeterred, the ailing Brown then had his law clerks bring work to the hospital and later to the assisted living center while he recuperated. His law clerks were with him virtually non-stop, taking turns to be there except at night during the past few weeks.

Brown was appointed as a federal district judge in 1962 by then-President John F. Kennedy.

“When Judge Brown spoke, we listened because— while nobody has seen it all — he certainly came closer to it than anybody I have ever known,” Marten said. “And his message was always the same: remember who you are and what your job is.”

In 1979, Brown officially took senior status, a type of semiretirement that allows federal judges to work with a full or reduced case level. He continued to carry a full workload for decades.

“I do it to be a public service,” Brown said in the AP interview. “You got to have a reason to live. As long as you perform a public service, you have a reason to live.”

His long tenure on the federal bench surpasses even that of Joseph Woodrough, a judge on the U.S. Court of Appeals for the 8th Circuit who, until Brown, had been the longest practicing judge in the federal judiciary when he died in 1977 shortly after turning 104.

“Judge Brown always said he hoped he would be remembered as a good judge, not just an old judge — and I think it was a sincere concern of his,” U.S. District Judge Eric Melgren said.

As a federal judge, Brown could have retired at full salary, but he never had a real interest in that, Melgren said.

“He frequently encouraged — or, you know, frankly even admonished us — to remember that our duty as judges was to take the responsibility for the administration of justice in our courtrooms and collectively in our district court,” Melgren said. “He was very committed to it.”

Brown’s stooped frame nearly disappeared behind the federal bench during hearings. His gait was slower, but his mind remained sharp as he presided over a tightly run courtroom even after turning 104 last June.

Brown removed himself from the draw for assignment of new criminal cases in March, and by the time he died he was no longer presiding over hearings. He kept an active civil caseload, but during the last months of his life referred evidentiary hearings on his remaining civil to magistrate judges for their recommendations before making a decision.

“I will quit this job when I think it is time,” Brown said last year. “And I hope I do so and leave the country in better shape because I have been a part of it.”

Another of his law clerks, Michael Lahey, said he took a turn for the worse just a week before his death.

“He finally wore out,” Lahey said. “He maintained his abilities right up to the end.”

Among the cases he was still handling when he died is a constitutional challenge to a new Kansas law restricting insurance coverage for abortions. He also was presiding at the time over a multi-defendant lawsuit filed by Omaha-based Northern Natural Gas Co. in its bid to condemn more than 9,100 acres in south-central Kansas to contain gas migrating from an underground storage facility.

Assistant U.S. Attorney Brent Anderson has practiced law in Brown’s courtroom for 20 years as a federal prosecutor and for more than seven years before that as a private attorney.

“Judge Brown ran his courtroom in a firm and fair manner so you knew when you were going into Judge Brown’s courtroom you had better know the rules and you had better follow the rules,” Anderson said. “On the other hand, there was no more compassionate judge than Judge Brown.”

Anderson recalled an incident that occurred when Brown was about 98. A cell phone started ringing in the courtroom — twice. Nervous lawyers pulled out their cell phones to make sure they were turned off. Then, while sorting through some paperwork on the bench, the judge realized it was his own cell phone that had gone off.

“He immediately fined himself $100 and held himself in contempt and said, ‘I guess I learned my lesson,'” Anderson recalled.

Brown — who was born on June 22, 1907, in Hutchinson, Kansas — was six years older than the next oldest sitting federal judge. At least eight other federal judges are in their 90s, according to a federal court database.

Brown started his career with the law firm of Williams, Martindell and Carey in Hutchinson. He graduated from the Kansas City School of Law, which later became the law school for the University of Missouri-Kansas City. Except for two brief breaks from the firm — one at age 27 when he was elected Reno County attorney and the other at age 37 when he joined the Navy — Brown spent his Hutchinson career practicing law there. In 1939, he became a partner.

He moved to Wichita at age 50 after receiving his first federal appointment as a bankruptcy judge in 1958. Four years later, he was appointed a federal district judge.

He outlived two wives and only moved into an assisted living center in recent years.

“His impact is more than he lived to be 104,” Melgren said. “He was a model for us for how we are to conduct ourselves as judges.”