Piatt County Circuit Judge John P. Shonkwiler, a longtime 6th Circuit chief who ruled on cases for nearly five decades, died Wednesday night at age 79.

Shonkwiler practiced law for just three years before he started his judicial career in 1965. And, he remained a relentlessly hard worker who devoted his entire life to law, his colleagues said.

Shonkwiler never married or had children, which fellow judges and local attorneys said allowed him to spend every spare moment on his docket and leadership posts on multiple judicial committees.

"He would have kept on going as long as his abilities were still strong — and they were," said Moultrie County Presiding Judge Daniel L. Flannell, who took over for Shonkwiler as 6th Circuit chief judge this year. "He loved what he did and his performance showed it. He was a workhorse of the judiciary."

In May, Shonkwiler announced his plans to retire effective July 31. Just a few days after that news, Flannell said, Shonkwiler underwent heart surgery. He never fully recovered and died of complications from the procedure and the heart disease he battled with for many years, Flannell said.

Even in his final months on the job, Shonkwiler walked several blocks to work every day, colleagues said, and could often be found in his office late at night and on weekends.

James L. Ayers, a partner at Shonkwiler & Ayers in Monticello — the law office Shonkwiler's father ran for years — drove past the courthouse on Christmas last year, just to see if the aged judge came to work that day. He did.

"I never dreamed he would die without being carried out of the courthouse — and he came very close to that," Ayers said. "He lived his life through his work."

Born in 1933 in Decatur, Shonkwiler graduated from the University of Illinois in 1955 and from Northwestern University School of Law in 1962. A retired captain of the U.S. Navy, he continued to work in intelligence for many years in the Naval Reserve.

He spent three years at his father's practice, then received an appointment as a magistrate judge in 1965. He began serving as an associate judge in 1971 and a year later became a circuit judge. He won several re-elections bids, most recently in 2010.

Shonkwiler became chief judge of the 6th Circuit in 1994, and chaired three committees for the Conference of Chief Circuit Judges. He also served as president of the Illinois Judges Association in 1983.

Chief Fayette County Circuit Judge S. Gene Schwarm, chairman of the chief judges conference, said Shonkwiler provided incredible amounts of institutional history to the group.

Shonkwiler carried extensive knowledge of topics including contempt of court law, the handling of traffic citation forms and fines and the statewide standardization of court forms.

"He was looked at as the ultimate authority in the state of Illinois in those areas," Schwarm said. "Whatever needed to be done, he was willing to do it."

Though devoted to his work, Shonkwiler maintained a bright sense of humor, Schwarm said, often making light of his age by referring to his early days as a judge as "pre-Civil War."

Illinois Supreme Court Justice Rita B. Garman, who met Shonkwiler decades ago, described him as calm and analytical and a judge who brought a measured approach to all matters.

When Garman formed a screening committee to review candidates for Shonkwiler's judgeship, he wanted to discuss attributes of potential successors, she said — even while in the hospital.

"He was always serious about what he was doing," Garman said. "But he also had concern for other people. That came across very strongly."

William F. Tracy II, a partner at Miller, Tracy, Braun, Funk & Miller Ltd. in Monticello, said most local attorneys spent their entire careers practicing in front of Shonkwiler and not seeing him in court will seem unusual.

"Everybody knew him — he was an institution," Tracy said. "He literally has been a fixture there."

As Flannell prepared to become a judge in 1988, he said he often sat in Shonkwiler's courtroom, noting the way he intently listened to both sides in a case.

"If you handled things the way he did, you weren't going to get it wrong," Flannel said. "If we could model all of us in his example, we'd be very well off."