linguistic:paraphrasing, structural:expansion
Presidency

While Fianna Fáil remained popular among the electorate, 75-year-old de Valera had begun to be seen by the electorate as too old and out of touch to remain as head of government. At the urging of party officials, de Valera decided to retire from government and the Dáil and instead seek the presidency of Ireland. He won the 1959 presidential election on 17 June 1959 and resigned as Taoiseach, Leader of Fianna Fáil and a TD for Clare, six days later, handing over power to Seán Lemass.

De Valera was inaugurated as President of Ireland on 25 June 1959. He was re-elected President in 1966 aged 84, which until 2013 was a world record for the oldest elected head of state. At his retirement in 1973 at the age of 90, he was the oldest head of state in the world.

As President of Ireland, de Valera received many state visits, including the 1963 visit of the US president John F. Kennedy. Five months later de Valera attended the state funeral for Kennedy in Washington, D.C., and accompanied a group of 24 Defence Forces cadets who performed a silent drill at his gravesite. In June 1964, he returned to Washington, D.C., as the second President of Ireland to address the United States Congress.

In 1966, the Dublin Jewish community arranged the planting and dedication of the Éamon de Valera Forest in Israel, near Nazareth, in recognition of his support for Ireland's Jews.

In January 1969, de Valera became the first President to address both houses of the Oireachtas, to mark the fiftieth anniversary of the foundation of Dáil Éireann.

In 1969, seventy-three countries sent goodwill messages to NASA for the historic first lunar landing. These messages still rest on the lunar surface. De Valera's message on behalf of Ireland stated, "May God grant that the skill and courage which have enabled man to alight upon the Moon will enable him, also, to secure peace and happiness upon the Earth and avoid the danger of self-destruction."