This article originally appeared in the The Inquirer in 2007.

In July 1957, Patrick Gibson's father - a Reading Railroad engineer - had just died in a train crash, but the 11-year-old boy found it within himself to send his allowance to the Philadelphia Police Department.

The money was for the funeral for an unknown boy whose nude and undernourished body had been found wrapped in a blanket in a box dumped in a field in the city's Fox Chase section.

"I would like to help make this little boy's burial as nice as my Daddy's," young Patrick wrote from his home in Lancaster.

Each city has its unsolved crime that echoes through the years. In New York, it is the disappearance of Judge Joseph Force Crater. In Los Angeles, it is the the slaying of Elizabeth Short in 1947, known as the Black Dahlia murder case. And in Philadelphia, it is the discovery of the "Boy in the Box" on Feb. 25, 1957.

The file for case No. H-57-22 fills eight boxes at police headquarters. The material includes photographs, the autopsy report (cause of death: beating), an invoice for the boy's original coffin ($35), a piece of the blanket, reams of investigative reports, and even Patrick Gibson's card.

Altogether, the contents can shed light on one of the most investigated cases in city history, except for the one thing that could help break it - the victim's name.

And while a police detective is assigned to oversee the case and members of the Vidocq Society - a Philadelphia-based group of professional and amateur sleuths - are working to develop leads, chances dim each year that the boy's identity will ever be known.

The details of the case, however, remain fixed in time.

That Feb. 25, a 26-year-old La Salle College student who was known to spy on the Good Shepherd home for girls on then-rural Susquehanna Road in Fox Chase saw across from the home a large box for a J.C. Penney bassinet with what looked like a doll or possibly a child inside.

The student did not report his discovery to police until the next day after hearing a radio report of a missing child in New Jersey and talking to a priest.

The radio call to check the box went to Officer Elmer Palmer, a father of young children.

"It wasn't a doll. It was a child," Palmer recalled in a recent interview.

As it has with others involved, the case has stuck with Palmer, and over the years he has visited the boy's grave.

"It was tough," the long-retired officer said. "It's something you don't forget... . This was the one that bothered everybody."

The boy's blond hair had been crudely chopped. His hands were wrinkled from being in water right before he was killed. He was about 4 or 5 years old. Because of the cold weather, it was hard to tell how long he had been dead, possibly three or four days.

Police took the unusual step of issuing a poster of the dead boy's face with pictures of the box and a cap found at the scene. About 10,000 copies were posted on stores around the city. Investigators even dressed the body in children's clothing to make the boy more recognizable.

One theory was that he was Steven Damman, who was 34 months old when kidnapped outside a Long Island supermarket in October 1955. (The Damman connection was finally ruled out in 2003 after a DNA analysis.) All authorities really knew in 1957 was that the child had been beaten and malnourished and probably killed by a parent or caregiver.

Tom Augustine, the detective who oversaw the case for a decade before retiring, and Bill Fleisher, commissioner of the Vidocq Society, saw the posters as boys and were deeply affected.

"It was very heartbreaking for me as a kid," said Augustine, who was 11 at the time. "It could be you. It could be your brother."

"I was literally stunned," said Fleisher, who was 13 when he saw the poster at the Penn Fruit store on City Avenue.

Many tips came in. Someone reported seeing the boy with a man in a restaurant in Camden. A man reported seeing a woman and a boy getting something out of a trunk off Susquehanna Road the day before the La Salle student spotted the box. None checked out.

William Kelly, a civilian in the Police Department's identification unit, checked footprints of infants at area hospitals.

He sorted through thousands for the years 1951 through 1953 and to this day wonders whether any of the poorly taken footprints he could not read might have belonged to the boy.

Kelly later examined 11,200 entry photos of Hungarian refugees who had arrived in the United States in 1956. He found 10 photos of children who could have been the boy, but all were tracked down.

Kelly, 79, continues to investigate the case as a Vidocq Society member with Joseph McGillen, also 79, an investigator for the Medical Examiner's Office when the body was found.

"It's been a labor of love," Kelly said. "My only regret is that I don't have another 50 years to give."

On July 24, 1957, with detectives as pallbearers, the boy was buried in a Philadelphia potter's field. A donated headstone said, "Heavenly Father, Bless This Unknown Boy."

In 1998, the boy's remains were exhumed, and mitochondrial DNA was extracted from a tooth. He was reburied in Ivy Hill Cemetery with a new headstone: "America's Unknown Child."

For Vidocq Society members, the most intriguing lead came in 2002 from a woman identified only as M. and now living Ohio.

In a meeting, M. told Augustine, Kelly and McGillen that the boy had been a child her late mother bought when he was a toddler and regularly sexually abused. His name, M. said, was Jonathan, and he was kept in the basement of their Lower Merion home. M. said she had helped her mother dispose of the body.

Fleisher and Kelly said there was nothing to disprove M.'s story, but nothing to prove it, either.

Now living in West Chester, Patrick Gibson said he had forgotten what he wrote in his card and how much money he sent for the boy's funeral.

"I never totally forgot" the case, he said, "but I haven't though about it for years."

Recently, police said Detective Regina Byarm had been assigned to oversee the case. She was not even born when the case first made headlines.

Contact staff writer Joseph A. Gambardello at 215-854-2513 or jgambardello@phillynews.com.