Pushing back at one-sided portrayals of the Irish as key creators of exclusionary national and racial identities, the author follows a group of middle-class intellectuals and activists known as Young Ireland, charting their legacy in Ireland, Australia, and the United States in the mid- to late nineteenth century, in part through their “international misadventures” (8).

Starting in Ireland in 1842, McMahon describes how young rebels Thomas Davis, John Blake Dillon, Charles Gavin Duffy and others forged from European racial discourse and the Celtic Revival a philosophy of “Celt and Saxon” to fan the flames of Irish independence. The Celtic spirit, Young Ireland argued, chafed against Saxon rule; nation-states needed the right balance of l'esprit et les lois. This notion of a Celt/Saxon dichotomy, expressed prominently in the rebels’ newspaper the Nation, inadvertently hurt Irish nationalist efforts to unite Protestants and Catholics, who fell on either side of the imagined split. And Young Ireland's regard for nonwhite peoples remained contradictory and contingent. The group might denounce aboriginal suffering, especially if it came at the hands of the British, but could not support Repeal leader Daniel O'Connell's abolitionist crusade for fear of jeopardizing Irish standing in the United States.

Yet once famine and economic pressure pushed the Irish abroad, Young Ireland's racial discourse proved a flexible template for a new Irish identity. Among Irish exiles and immigrants to eastern Australia in the 1850s McMahon finds the “early inklings of Irish global nationalism” (44–45). Irish success in the Antipodes proved it was English misrule, not Irish racial shortcomings, that stymied the Celt. Slowly, the primordial Irish connection to Ireland's soil evolved, through a web of internationally circulated Irish newspapers, into something more mobile, as Irish migrants became part of a “transnational imagined community” (75).

Three of McMahon's five chapters concern the Irish in the United States. In battling American Anglo-Saxonism, Irish American editors hyped Irish contributions to US democracy and posited the mobile Celt as a universal carrier of republican ideals. Irish American editors routinely described the United States as, in the words of James McMaster's Freeman's Journal, “a curious but, we think, not undesirable mixture of … various nationalities” (quoted at 94). But how much did the Irish fortify notions of whiteness in their quest to widen the borders of American belonging?

McMahon's complaint with whiteness studies is that its practitioners have “overemphasized the host country's role in immigrant identity formation, gone some distance toward blaming the immigrants for the American racial structure, and largely missed Irish America's connections to the outside world” (5). On these grounds he succeeds in demonstrating strong transnational identities among the Irish, and the complexities of the support of some Irish Americans for, for example, the US Confederate South. Though he tries to pull no punches when recounting Irish bigotry – the book describes New York City's draft riots as a particularly vulgar expression of Irish white supremacy – McMahon sometimes picks on the weaker whiteness scholarship, while imagining global, mobile identities as naturally more egalitarian than those tied closer to (one) home. On this latter point, Kornel Chang and others have shown that, at least on North America's western coast near the turn of the century, it was precisely a transnational, white working-class identity that Irish, Cornish, Scotch, and English miners promoted globally, traveling to speak at anti-Asian rallies in white settler colonies around the Pacific.Footnote ¹

McMahon could also engage more deeply and critically with his newspaper sources. He rarely ventures beyond describing newspapers as “facilitating the transmission of ideas” (110) and providing a “transnational public sphere” (75). The materiality of the press – its text, sections, and illustrations – or journalism's influence as both business and profession on Young Irelander thought remain mostly unexplored. Granted, such inquiries might make for a different study altogether. At minimum, one feels McMahon occasionally allows the opinions of a relatively elite group of activist editors to represent the Irish, and Irish identity, as a whole.

These problems do not overshadow the book's strengths and achievements. One comes away from Global Dimensions convinced, for example, of the absurdity of locating the origins of American cultural pluralism or cosmopolitanism in the late nineteenth or early twentieth centuries (perhaps with pragmatists William James and John Dewey, or with Randolph Bourne's 1916 essay “Trans-national America”). As McMahon demonstrates time and again, Irish intellectuals and activists worked diligently and much earlier to expand American citizenship to include multiple loyalties and heritages. The book's intriguing excavation of the roots of Irish “global nationalism” and its development should similarly open new vistas in the study of Irish identity, nationalism, and migration.