|... we know that of the 1,357,831 who left between 1885 and 1920, 684,159 were female; of these, 89% were single and most were under the age of 24. [Hasia] Diner remarks that this constituted a mass female movement without parallel in the history of European emigration and a 'defeminization' of the Irish countryside.
Ann Rossiter, 'Aspects of Irish women's emigration experience' in Sean Hutton & P. Stewart (eds.), Ireland's histories, London, 1991, p.225.
Before the Famine, about two thirds of those who emigrated were male and probably most of the females who accompanied them at that time were wives and children travelling in family groups. More reliable records, available towards the end of the nineteenth century, show how the proportion of females leaving Ireland had grown to equal - and at times to surpass - that of males.
From Commission on emigration and other population problems 1948-54, Stationery Office Dublin 1954. Quoted in Pauric Travers, 'Irish female emigration 1922-71' in Patrick O'Sullivan (ed), Irish women and Irish migration, London, 1995, p.148.