Among the scattered notes taped to the door of the Irish author Colum McCann’s home office in Manhattan is a photograph of James Foley, the American journalist who was murdered by members of the Islamic State in August 2014. In the picture, he leans against a barricade of sandbags in jeans and a flak vest, reading McCann’s novel “Let the Great World Spin.”

McCann was so moved when he saw the image shortly after James Foley’s death that he reached out to Diane Foley, his mother, to offer his condolences — and his help telling her son’s story, should she ever want it. But Foley missed the message.

She was busy creating the James W. Foley Legacy Foundation, an organization focused on protecting journalists and ensuring the freedom of Americans held hostage or wrongfully detained abroad. And she was still grieving a son who had been held kidnapped while covering the Syrian civil war and held for 21 months before he was executed on camera, with the footage then released online.

Then, in 2021, McCann and Foley found themselves on the same Zoom call. It was for a Marquette University book club; the group was reading another of McCann’s novels, “Apeirogon,” and Marquette was James Foley’s alma mater, so his mother had been invited. This time, they connected.

“It was serendipitous,” Foley said, seated next to McCann in his living room, in Manhattan. “Colum reminded me of Jim in a lot of ways, just in his goodness and his ability to put very profound feelings into words.”

Within a month of their Zoom call, McCann was visiting the Foleys’ New Hampshire home to discuss what would eventually become “American Mother,” a hybrid of biography and memoir due out in the United States by Etruscan Press on March 5.