The peaceful pine forests of Camden, South Carolina, have spent centuries hiding a secret as old as America itself. In August 1780, British and American soldiers clashed there, leading to a terrible defeat for the Continental army.Battlefield archaeologists Jim Legg and Steve Smith have been studying the site for decades, but recently, they made a shocking discovery: The sandy soil was home to several sets of remains buried in shallow graves. Metal buttons suggested the men had been Continental soldiers, but there was no other identification. Remains were given numbers instead of names.About 2,000 Continental soldiers were killed, wounded or captured, and some men never returned home. Their families could only guess at their fates. But Legg and Smith’s discovery, paired with an explosion in DNA technology, is changing what’s possible.AdvertisementAdvertisementA set of remains, previously known only as 9B, has been identified as John Pumphrey, a young man from Maryland who enlisted in the Continental Army’s 7th Maryland Regiment as young as 13.Allison Peacock, a genetic genealogist who uses DNA and family trees to identify remains, said researchers used “three different types of DNA” and biographical data to make the identification. Identifying the remains at last puts “goosebumps on her arms,” she said.The Pumphrey family has deep Maryland roots, historic records show. The famil …