President John F Kennedy’s visit to Ireland in June 1963 just months before his assassination offered Sean Lemass the opportunity to put forward an image of a new Ireland to the world.

“I think Kennedy’s coming to Ireland was a tremendous success,” he remembered. “National prestige was enhanced, morale was raised and we gained in international influence by reason of the fact that he came here.”

The international PR campaign worked superbly, topped for Lemass by his place on the cover of Time magazine a month after the visit – one of the marks of success in international politics at the time.

The globally-influential New York-based magazine lauded the modern, thrusting vision of a forward-thinking country that Lemass was trying to show the world.

Yet, Lemass did not warm entirely to Kennedy. He candidly admitted that he preferred Kennedy’s predecessor Dwight D Eisenhower – even he did not believe that Eisenhower had the “higher intellectual qualities” required.

“One could detect that his mind was working, but one could not know what it was producing. Kennedy’s eyes were the most striking, they were almost expressionless. Even when he was joking or laughing he was coldly calculating the effect he was having on listeners.

“But I liked Kennedy very much and I think he had an enormous impact on the world and could have had enormous influence on the future of the world because of, firstly, the originality of his approach to matters of public policy, and secondly his intellectual capacity to argue his point of view.”

Arbour Hill Kennedy, Lemass observed, was a likeable person but all American politicians at the time were likeable people, he believed as a consequence of their training and the public relations people they employed.

Lemass’s personal highlight was Kennedy’s decision to lay a wreath at Arbour Hill where the graves of the leaders of the Easter Rising are buried.

“He was the first president or head of state to this. Since then there have been several others, but you would have to be alive in 1916 to realise the significance of this event – the head of the greatest state in the world coming to pay homage and respect to the men who had been shot at that time.”

Kennedy’s speech in the Dáil garnered a standing ovation and many plaudits from those who were there, but a joke he made fell flat with President Éamon De Valera.

Looking around the Dáil chamber, Kennedy remarked that “nothing good ever came out of Leinster House”.

Afterwards at Áras an Uachtaráin, De Valera told Kennedy: “Mr President, you did no good to Irish politicians by using that quotation”.

Kennedy ordered his press officer to delete the reference from the version of the speech circulated to the media.

What happened next amazed Lemass. “An enormously efficient organisation immediately sprang into action to kill the quotation, so that it does not now exist anywhere”.