John Berne Hannum, 92, of Unionville, a U.S. District Court judge for 23 years, died of heart failure Monday at home.

In 1969, Judge Hannum was appointed to the U.S. District Court for the Eastern District of Pennsylvania by President Richard M. Nixon.

Judge Hannum's decisions in civil proceedings included issuing a restraining order to prevent a Conrail strike, and reversing the 1973 dismissal of a Philadelphia firefighter for refusing to trim his Afro.

In criminal proceedings, he sentenced doctors convicted of Medicare fraud and druggists convicted of illegally selling depressants and opiates, and he sent numerous cocaine, heroin, and crack dealers to jail.

In 1988 Judge Hannum gave a small-time drug dealer, who had fathered three children out of wedlock, probation instead of hard time, provided the dealer would refrain from what the judge called "fornication and bastardy."

Though he was a consummate gentleman, his son, John "Jock" Jr. said, he was stern and had high standards.

He loved horses and dogs, his son said, but gave up fox hunting when he became a judge because he didn't want to be distracted from work. For exercise he walked, his son said, and often traveled on foot from his farm in Unionville to the Brandywine Battlefield, a round trip of more than 20 miles.

Judge Hannum grew up in Elwyn and graduated from the Lawrenceville School. He attended Princeton University, where he was 155-pound champion on the boxing team. He earned a bachelor's degree from Franklin and Marshall College and earned a law degree from Dickinson School of Law.

He enlisted in the Navy the day after Pearl Harbor. During World War II, he was skipper aboard two submarine chasers that were also used in rescue operations.

After his discharge, he returned to his father's law firm in Chester and later was a litigator with the firm of Pepper Hamilton in Philadelphia. He served as a Pennsylvania Superior Court judge for a year before being appointed to the federal court.

From 1962 to 1964, Judge Hannum was chairman of the Republican Committee in Chester County. For 21 years he served on the board of the Unionville-Chadds Ford School District. He also served on the boards of Lincoln University, Chester County Hospital, and Dickinson School of Law.

Since 1940 he had been married to Nancy Penn Smith Hannum. They had met fox hunting - his father was master of hounds for a Delaware County hunt club and her stepfather owned Mr. Stewart's Cheshire Foxhounds in Chester County.

The couple executed a conservation easement in 1991 for a 1,208-acre tract they owned in Unionville to preserve it from development.

In addition to his wife and son, Judge Hannum is survived by another son, Richard "Buzz"; a daughter, Carol Davidson; nine grandchildren; and four great-grandchildren.

A memorial service will be at 3 p.m. May 2 at Church of the Advent, 401 N. Union St., Kennett Square.

Contact staff writer Sally A. Downey at 215-854-2913 or sdowney@phillynews.com.