“Now I work here — to realize that this is my history, this is my story, blows me away,” said Mr. Alexander, 45, an executive assistant in Georgetown’s office of technology commercialization. “I have been really emotional as I learned about my ties to the university.”

The journey began with Mr. Alexander’s own digging to find out more about his lineage, to find out more about the ties that bind. He wanted to know more not just for himself, but for his 9-year-old son.

Mr. Alexander had his DNA tested in 2014, along with that of his wife and parents, and worked on a family tree on an ancestry website. But that search ended at the name of his great-grandmother, Anna Jones — the granddaughter of Anna Mahoney Jones. But for Mr. Alexander, it was just a name, no story attached.

The path backward might have stopped there, if not for an unexpected email. Last fall, Mr. Alexander heard from a woman in Boston, Melissa Kemp, who turned out to be a distant cousin. They had a conversation on the day before Thanksgiving, each recounting the century-old names of relatives they shared, including Anna Jones.

Ms. Kemp went back two more generations and introduced Mr. Alexander to the name that would come to define his earliest known roots and reveal his connection to Georgetown: Anna Mahoney Jones.