Decades of Black history were lost in an overgrown Pennsylvania cemetery until volunteers unearthed more than 800 headstones

North York, Pennsylvania CNN — Before she became one of America’s most-decorated Special Olympics athletes, before the made-for-TV movie and the shared stages with actor Denzel Washington and Presidents Bill Clinton and Barack Obama, Loretta Claiborne was a great-granddaughter – of one Anna Johnson. Not until two decades later did Claiborne learn that a group of volunteers called Friends of Lebanon Cemetery had found Johnson’s grave marker. Cemetery records, newspaper articles and ground-penetrating radar now indicate more than 3,700 souls rest at Lebanon – many of them tightly situated, leaving geophysicist Bill Steinhart, who has surveyed most of the cemetery, to say, “If they’re not touching, they’re nearly touching.” Samantha Dorm poses by a headstone for the Fells family, one of many forks in Dorm's sprawling family tree. She showed off Ida Grayson’s home, which was featured in “The Negro Travelers’ Green Book,” and the former site of the city’s first “colored school” helmed by educator James Smallwood, who is buried at Lebanon. “There’s a running joke when we find someone: ‘Oh, Sam’s probably your cousin.’” Mary Wright, Bill Armstrong, Amaya Pope and Dwayne Cowles Wright, from left, tidy family members' gravestones.