"When you can trace your ancestors back that far, it feels . . . historic," says Wilson, who grew up in East Camden.
He discovered Garman inadvertently about 15 years ago, after a professional hired by a relative to locate overlooked family assets did not turn up any cash.
"Instead, we got a gem," Wilson says. "We found out that we were related to this Civil War soldier.
"That really galvanized me. I started researching Garman. . . . Since then, I've even retraced his steps in battlefields."
Other serendipitous events have since helped him make additional connections.
In 2002, for the first time, Wilson visited Garman's grave at Greenwood Cemetery in Northeast Philadelphia. Concerned about the condition of the burial plot, he spoke to a cemetery employee, who gave him a business card left by a Florida man who had recently visited the grave.
The man was George Meade Garman III, great-grandson of the Civil War soldier. Before his death, he sent Wilson, a distant cousin, a Bible that their ancestor had carried into battle. The pocket-size volume is the centerpiece of Wilson's impressive Civil War memorabilia collection.
In July, Souder, an amateur genealogist, was researching his family tree online when he found a 2006 Camden Courier-Post column I'd written about Wilson and his commitment to researching and documenting Garman's life.
"I realized that Joe and I had the same great-great-grandfather," says Souder, 67, a retired RCA Camden employee. "It was quite a surprise."
He called Wilson, his second cousin, and the two shared information about their great-great-grandfather. "I didn't know too much about him," Souder says, "and Joe had done a lot of research."
Souder gave Wilson copies of documents he'd discovered during his own research - "I haven't found everything, but I've written my family tree." Mary Garman Wilson's connection by marriage to a venerable Maryland clan named Dawson - and through them to Graves - had been documented and posted online by MacDonald.
"I've researched and written up histories of 300 families," MacDonald, 69, tells me.
A retired manager with the U.S. Department of the Interior, MacDonald got into genealogy by researching the Stone branch of his family, whose roots reach back to the earliest days of colonial America. All the way to Thomas Graves - which makes him another distant cousin of Wilson.
"I've always been interested in history, but in school, you learned about the generals and the admirals," MacDonald says. As a genealogist, he adds, "you find out that your relatives were the privates and the corporals. All of a sudden, history becomes real because it's your people."
Wilson agrees. He had been to Jamestown before, but when he visited after finding out about his link to Graves, "I thought, 'Hey, I'm a direct descendant of one of the guys who landed here.' "
At my suggestion, Wilson and MacDonald spoke for the first time Wednesday by phone. Afterward, both told me the documentation for Wilson's lineage looks solid.
Like Souder, Wilson and MacDonald have relied not only on family lore or names inscribed in heirloom Bibles (although both such sources can be useful), but also on birth and death certificates, marriage licenses, property records, wills, and other primary-source materials.
"I just want to get it right," says Wilson, who lectures and exhibits artifacts for historical societies and school groups in South Jersey.
Adds MacDonald: "I've never copyrighted any of my research, because I just do it for fun.
"One way or another, we're all related."
E-mail Joe Wilson at email@example.com.
Contact Kevin Riordan at 856-779-3845 or firstname.lastname@example.org, or follow on Twitter @inqkriordan. Read the metro columnists' blog, "Blinq," at www.phillynews.com/blinq.