Legal career In 1937, during the government of
Éamon de Valera, he was working as a legal expert in the
Department of External Affairs when de Valera called on him to assist in the writing of the new Irish constitution, which would replace the 1922
Constitution of the Irish Free State. With
Maurice Moynihan, Hearne drew up the first draft of the constitution; according to Moynihan, Hearne had been instrumental in convincing de Valera that a new constitution was necessary in the first place. The exact role of Hearne is not evident from the remaining documents; it is not clear who actually wrote the first draft, and according to the Irish historian
J. J. Lee, "Much remains to be uncovered about the planning and drafting of the constitution, including not least the roles of John Hearne, the legal adviser to External Affairs, and of Maurice Moynihan."
Diplomatic career After his legal career, Hearne filled a number of diplomatic positions. In 1939, he was appointed
High Commissioner to
Canada. In March 1950, he became the first
Irish ambassador to the United States, It was Hearne who began the tradition of presenting a bowl of
shamrock to the sitting
U.S. President at the
White House on St Patrick's Day. In 1954, he gave the commencement address at
Boston College, and on that occasion was awarded with an honorary degree. In 1960, after retiring from the diplomatic service, he became a legislative consultant to
Nigeria and
Ghana, which had recently acquired independence, albeit within the Commonwealth. A bust of Hearne by Elizabeth O'Kane was unveiled in his native
Waterford on 3 July 2017 on the 80th anniversary of the constitution. There is a replica in the Irish Embassy,
Washington, D.C., and a replica stands in the garden of
Iveagh House, headquarters of the Irish Department of Foreign Affairs. A biography of Hearne, "John Hearne: Architect of the 1937 Constitution of Ireland" by Eugene Broderick was published in 2017. ==References==