Andrew Staton, 17, a researcher for Genealogytrails.com, said the finder discovered the purple heart in a record player purchased from a flea market at the Anderson Jockey lot in Belton, WHNS-TV, Greenville, reported Monday.
Stanton said the finder brought his search for the medal's rightful owners to the website, and he began looking for information on Sgt. James Carithers.
The teenager said he found a post from 2000 on a genealogy website from a woman seeking information about family members including Carithers.
The woman, Arrista Pottle, identified herself as Carithers' niece and said he had died before she was born. She said her mother did not often speak of her brother.
"I guess it was still very painful for her that he had died when he was very young," Pottle said.