“It was magic,” he said, “I never saw the course. I didn’t study it. I just ran it.”

As one of the elder statesmen in the elite field, he could feel the crowd turning him into a sentimental favorite. Tuliamuk, too, said she drew energy from the thousands who lined the course and screamed for her.

“The cheering on the course was so loud,” she said. “A lot of the time, I felt like my ears were ringing.”

A handful of Saturday’s top finishers can tell similar stories of their rise to elite competition for the U.S. They were born abroad in East Africa — Tuliamuk, Kipyego, Korir and Maiyo in Kenya; Abdirahman in Somalia — and moved to the U.S. to attend college but then essentially never left. They live and train largely in the U.S., though Abdirahman and Kipyego have made occasional jaunts to Africa to train, as many runners around the world do.

“For me to represent this country is a privilege and honor,” said Kipyego, 34, who has long been one of the world’s top female distance runners. “I wanted to run for this great nation because of the privileges and opportunities that this country has afforded me and my family. And the best way to do that is to do it represent the country well.”

In Japan, they will join scores of athletes who were born in one country and will compete for another. Given where they started, they may be as surprised as anyone to be marching in the opening ceremony under the American flag, though perhaps not as shocked as Seidel or Riley.

Seidel, who had one of the great college running careers at Notre Dame, then struggled with disordered eating and hip surgery, was in a daze long after she crossed the finish line.

“I keep saying I don’t know what’s happening,” she said, a silver medal hanging around her neck.

Riley, owner of a similar silver medal, said he always envisioned making the Olympic team, even if he didn’t actually believe it would happen after having to sit out for two years with injuries. Now he will head to Japan this summer and race in the mountains of Sapporo, site of the marathon, which had to be moved from Tokyo because of concerns about heat.