They are relatives of his grandmother Katie Doyle and her sister Mary, who left their homeland in 1890. For the Doyles in Ireland, it will also be an emotional "reunion," as the sad story of those who'd left had survived through the generations.
"He's over the moon. He has just one brother left out of a family of nine," said his daughter, Monmouth Junction, N.J., resident Laura Ryan, who initiated the search. "So, just when you thought you were done, there is this whole other family."
The first clue came after one of John Ryan's sisters died in 2001. A 1936 letter postmarked "Castlebridge, Co. Wexford" was found in her papers. It was a request for some documents and signed "your cousin Thomas."
Two years later, a friend of Laura Ryan's was randomly seated at a wedding next to the wife of a friend. The other guest was Celestine Rafferty, a local historian from Castlebridge, Co. Wexford. The friend told Rafferty about Laura Ryan's possible connection to the town. The historian soon got to work. By the time that the Ryans traveled to Wexford later that year, she had located Katie Doyle's birth certificate and had determined where precisely she had come from.
Rafferty greeted Katie Doyle's grandson: "Welcome home, John Ryan!"
"She took us to Screen parish church and then to the townlands of Curraclo and Kilmacoe, where our family originated," recalled Laura Ryan. "We were overjoyed."
On a subsequent visit to Wexford in 2008, she left a note in a ziplock bag on the grave of Moses Doyle, her great-great-grandfather and Katie's father, with some details and her email address.
A week later a woman who was married to a Doyle replied. Soon, Ryan was in contact with her long-lost cousins, descendants of cousin Thomas, who had written the letter in 1936, and also those of William Doyle, Katie's younger brother.
"It was so lovely to hear that they were as excited as we were," she said. "They grew up hearing stories of the two sisters that went off to America, but never knew what happened to them."
William Doyle was as upset as any of the adults in the family at the departure of his adored older sisters Katie and Mary.
Now Katie's descendants will meet William's next week, 110 years after the sad farewells. The kin of 1936 letter-writer Thomas Doyle will also be there. "We've just found out that we will arrive on Thomas's birthday," she said.
John Ryan, his wife Anna, daughter Laura Ryan, her 16-year-old son Nicholas DiGirolamo, daughter Rita Hart and her 22-year-old son Evan Hart will make the trip on March 10.
"Nicholas and Evan want to be there to witness this for their grandfather," Laura Ryan said, adding that her son is in contact with a new generation of cousins on Facebook.
In the exchanged emails and letters, she discovered the origins of several family traditions. For example, John Ryan's Irish-American mother always went to the beach on Aug. 15, the Feast of the Assumption. That, it now turns out, was the local custom in the seaside town of Castlebridge.
"This is not only for me, or us," Laura Ryan said. "I felt I had to do this more for ancestors who are no longer here. So they may finally have peace knowing that their family has been reunited, no matter how long it took."
She recently received a letter from a Doyle cousin discussing the Ryans' upcoming visit, which said: "It is so wonderful that you are all coming. My grandfather would be so happy, God rest his soul, to have found his sister's grandchildren. He often spoke of his sisters when we were very young and didn't appreciate all he was telling us. I know they all will all be with us in spirit."