The Gaelic name O Deargain, the root of which is the adjective dearg (red), has taken the anglicized form Dargan in Leinster, and Dorgan in Munster. The latter is almost confined to Co. Cork (where there is a place-name, Ballydorgan) while respectable families of Durgan have long been resident in the midland counties. As a Gaelic sept they were of little importance so that they seldom figure in the Annals, the "Book of Rights", the Fiants, the "Topographical Poems", "An Leabhar Muimhneach" or any of the usual sources of genealogical information. There were two prominent nineteenth century men of the name: William Dargan (1799-1867), the chief builder of Irish railways and promoter of the Dublin International Industrial Exhibition of 1853; and Edmund Strother Dargan (1809-1879), the Irish -American judge, a remarkable character of whom many amusing anecdotes are told.