They had six children including five daughters Pearl (Binnie), Muriel, Cecil, Ita and Ethna, and a son Sarsfield.

Following representations by the Free State's government to London and Washington, and in particular to tackle the problem of anti-Treaty propaganda, this role was officially recognised in 1924.

[citation needed] Smiddy's appointment represented not only the establishment of the Irish Free State's first formal diplomatic relations with another country since secession from the UK, but also the first attempt by any British dominion or colony to appoint what would these days be regarded as an Ambassador to a third country.

Thereafter, he served on various Boards, and was head of Combined Purchasing Section at the Department of Local Government and Public Health from 1933 to 1945.

[citation needed] Throughout the late 1930s and the 1940s, Smiddy advised the de Valera government on economic matters.