I believe it was also 1957 on the site they have a date of 8/17/57 from the Philadelphia Inquirer (oh NeverMind I just saw it was answered above!! sorry)
http://www.americasunknownchild.net/Archives5Text.html#fourq
they also mention this missing woman and her kids but never hear anything after if they were found or not.. its kind of funny.. like ok its not the boy in the box move along next missing person...and they even have photos of the people missing
Homicide detectives have a fresh and exciting interest today in the case of the murdered boy of Fox Chase. A father came to police with a story that there is a chance the dead boy is his long-missing son.
Harold Sanders, 31, of Dover, Del., had a son who was fair, thin, about the age of the child found battered to death in a cardboard box at Verree and Susquehanna rds. Last February.
The father thus revived a search for his missing family-wife, two daughters, and a son. The father learned only recently about the murder, that the Fox Chase boy had not been identified.
Homicide Lieutenant David Brown said, "Even if it was not the Sanders boy, we are working on the strangest disappearance case in Philadelphia police records."
Missing without a trace are Mrs. Jean Sanders, 32, her daughters, Bonnie, 9, and Carol, 7, and son, John, more than 4, if still alive.