Little has been written of the optimism and excitement among Irish immigrants and other Americans during the revolutionary months of 1848, the European ‘springtime of the peoples’. Studies of Irish-American nationalism hasten over the mobilisation of funds and arms to register the impact of failure. The ignominious collapse of the Young Ireland rising in Widow McCormack’s cabbage patch was to compel Irish-Americans to reconstruct their identity, to redefine the ways and means of their nationalist project. Irish-American nationalism became self-enclosed and self-reliant, an attitude evinced in a pattern of ethnic associational culture extending from mutual improvement to terrorist planning. During the heady months of 1848, however, a different mood prevailed. Looking across the Atlantic to revolutionary Europe, Irish immigrants invoked an international republicanism in which America, their adopted homeland, held pride of place. By recalling their hosts to their revolutionary past, Irish-Americans challenged narrow isolationism — and ‘Know-Nothing’ prejudice — to gain substantial, if temporary, native support.