When Mr. Neiland graduated from high school, he said, every classmate, including him, left for the United States, Canada or Australia.

“I would never think of leaving this place for America now,” he said.

While the landslide result of the abortion referendum may have surprised much of the world, many Irish were less shocked. They have seen the changes in the country building over time.

Prime Minister Leo Varadkar, who is half Indian, spoke of a “quiet revolution that has been taking place in Ireland over the last couple of decades.”

Ireland’s impoverished past, as well as the outsize role of the Catholic Church, had set it apart from much of the rest of Europe. Many saw the referendum as the final step in aligning the country with the rest of the continent.

The vote, said Mr. Tyrrell, “cements us as a progressive nation.”

“It’s going to change the optics of how people view us after these two landslide victories,” he said. “I’m so proud of Ireland.”

Alan Barrett, director of the Economic and Social Research Institute in Dublin, said the results of the abortion referendum indicated a “convergence with European norms.”