‘I realised when I was very young that I would be going,” Joe Flannery says about his decision to leave Ireland in 1951. The Mayo man talks about it with a clarity that overrules any regret or bitterness or wishing that things could have been different. He made a choice that was as common as staying on the farm, going to Maynooth or signing up for the Pioneers. He left.

“I was the eldest of 14 children in a four-bedroom bungalow on a farm outside Castlebar. And all of a sudden it was very crowded. My mother was a great lady, and couldn’t do enough, but I realised I had to get the hell out. There was no room.”

Half a century in New York has taken little of the west-of-Ireland propriety out of Flannery’s accent, and if he has acquired an American aspect to his personality it is that he answers questions with a disconcerting directness.

But he is plainly and unequivocally Irish, just one of the tens of thousands who emigrated during that decade.

“The 1950s is always about people leaving,” Michael D Higgins said long before he became President of a country facing the latest chapter of departing youth.

But in the midcentury the exit was staggering: 80,000 people, almost all of them young, left in 1958 alone, uncertain whether, or when, they would be home again.

They were the vanished generation, conspicuous by their absence and represented by the deluge of letters they sent home, most containing the squirrelled dollars and sterling that were a blood transfusion to an ailing state.

In the Tiger-economy years there was a wistful and even nostalgic hue about the 1980s wave of emigrants, and there is plain anger about the great numbers of young people leaving Ireland now. But about those who left in middle of the 20th century, there has always been a quiet guilt and sorrow.

You can find plenty of that lost generation scattered around the five boroughs of Manhattan, and most will assure you that there is nothing to be sorrowful about.

Flannery spent most of his working life with the former airline Pan Am. “The airline of airlines,” says Flannery, who drops into the Irish Center in Long Island City every few days to meet friends and sometimes to have lunch or coffee.

County accents
When we meet there the day is sparkling and Flannery is flicking through his smartphone, showing pictures of his infant grandchild taken on a recent visit to his son in Hong Kong.

The social room is crowded, and most of the accents are still traceable to county origins. They lightly jibe and joke with Paul Finnegan, the director and energy behind the Long Island centre, who moved here from Galway in the late 1980s.

Frank Gordon, a spry 92-year-old, takes his place at his usual corner near the door and flings compliments at any woman who comes within earshot.

He is from Kiltyclogher, in Co Leitrim, and, like most men of his generation, gravitated towards England, volunteering for the British army, and serving on the front line in Sicily during the second World War, before deciding to try the US, in 1953.

“By then I was married and we had three children,” he says over a cup of coffee. “I worked on farms, and [two of] the children would come up to me with tea. They were five and three, an interesting age. And it was just so pleasant sitting there chatting to them. I came here without my wife, and that first year it was difficult. I realised then how people separate. I was 30 years old when I came here, and I didn’t even look it. I didn’t have to snap my fingers; women came to me. It was a learning experience about life in general, that year, and it was tough. It wasn’t that easy for us to pick up the pieces. But we did, and we lived together for 60 years, until she died, in 2007.”

Gordon was well travelled by the time he reached New York but was entranced by his first sight of the city. He sailed on the Mauretania: dense fog delayed their docking until the evening, and, as they moved slowly near the port, he stood beside a veteran emigrant who pointed out the name of each lit, spiralling building. "No movie could depict it. It was just gorgeous."

The fairy tale ended within weeks. He found the pace frantic and the pay dismal. “I worked for a grocer from the midlands; he exploited us.”

Flannery also found the early days testing. Like Gordon, he originally moved to England, where he spent nine years before getting itchy feet.

“I was betwixt here and Australia. But I had three aunts, Lord have mercy on them, here and three uncles, Lord have mercy on them, here. One of my aunts came here in 1924: the US was their life, and there was no place like it. But there was nobody sorrier than me when I came here in 1961.

“I felt out of place and uncomfortable, and it took a while. I lived with my uncle Tony at first and his wife, Mary: she was like a second mother to me. Without her I would never have survived.”

Julia Anastasio was raised on stories about New York when she was growing up in Co Offaly in the 1950s. Her parents had emigrated to New York as single people and met at a dance.

They took a boat to Ireland in 1938 with the intention of marrying, saying goodbye and then settling in New York. The second World War disrupted their plans, and they stayed in Ireland.

“I never quite understood how they could settle back into Ireland,” says Anastasio, who volunteers at the Irish Center.

“Here they had electricity and modes of transport and a car. Mother had worked for a gorgeous home in Long Island, and my father worked for the Transit [public transport]. Years later I asked one of my sisters if she thought Mother was really happy at home, and she said, ‘Yeah, she felt Ireland was a better place to have raised us.’ ”

Still, she is grateful that her parents encouraged her to try life on the other side of the Atlantic. She worked for AT&T and, later, the city health department, got married and, like thousands of others, wrote home faithfully.

Sending money home
Sending letters and money was usual. "I'm not ashamed to say I sent a lot money home," says Flannery. "Things were mighty, mighty tough.

“Letters were the only way. I believe it was almost $10 to make a call to Ireland. That was a hell of a lot of money. You had to go through an operator here and then one on the other side.

“There was a person I knew who worked with one of the airlines, and she told me, on many occasions, that I could call Ireland [from the company’s phone] whenever I wanted. I knew friends who did. She was eventually fired. She had something like a million bucks in phone calls racked up. It was better writing.”

The letter-writing was furious and automatic until the 1980s, and many letters survive in thousands of homes. Flannery was fortunate because he had free flights home through his job at Pan Am.

Anastasio also made regular summer visits to the family home in Geashill, but she began to see her childhood home through a different prism. She recalls her mother as “tough but loving underneath it all. I have no complaints. I don’t have much of her stuff now – I am a scarf lover, so I have some of those. But mostly just good memories.”

Anastasio’s sister visited Ireland in March and came back complaining that the weather was perishing.

Their frequent visits to Ireland have made it easy to monitor how the country has progressed, but Anastasio has met many immigrants who simply never went back.

“I would never ask why. I’m sure they have reasons. You don’t intrude on something like that.”

When she visits Ireland now she is incredulous at the preponderance of white mansions that have sprung up on the narrow lanes of the midlands and is constantly shocked by the price of coffee in restaurants. But for the most part she thinks Ireland has kept its character. “The people are nice. The young are maybe like the young people here, in that they don’t have too much time for you.”

Gordon last visited Kiltyclogher two years ago. He thinks his village is thriving and has no hankering after the place as it was when he left.

“It has changed wonderfully for the better. I don’t bemoan the fact that the thatched houses are gone, because the discomforts of those homes are gone too.

“Everyone has new houses now. Okay, some of them are not paid for, but they will be. There are a lot of cars there. Kilty had three cars when I was a kid – the priest, the grocer and another was a hackney that went out of business.

“The only thing I have missed is that going to Mass was a social event, and the car has taken away from that. You would walk the road and hear the scandal – who was the latest girl pregnant, who was blamed for it, was there a married man involved. All this stuff was meat and drink.

“My father never went to Mass, but my mother would have him enlightened when she came home. The more lurid the news, the better it was.”

Gordon gives a light, roguish laugh.

He is adamant that present-day Ireland is a better place. “To an extent it is bad that the young are leaving again. But Ireland is a different country.

“In my time in Ireland there was too much stress on nationalism and not enough attention to what was good for the populous. The young people now are making governments toe the line. The church is not allowed to run away with things in the name of God.”

Among those at the centre there is no sense of having missed out on life through their departure, though certain dates – “My brother was killed when he came off a rotten, stinking Vespa outside Castlebar in 1969,” says Flannery – are etched in their minds.

Few wish they had stayed. “Yeah, I think most of us are pretty happy with our lives here,” Anastasio says with a nod. “Yeah. Where I live, in Astoria, I can get a train to here to meet with people in 10 minutes. I can get to Manhattan in 15 minutes. The idea of living in Ireland . . . God, no. I could never take that weather.”