Dr Robert O'Sullivan

robert.osullivan@history.ox.ac.uk

I read History at the University of Cambridge, where I won the Gladstone Memorial Prize and the Junior Sarah Norton Prize. I then received my MPhil and PhD in History from the University of Cambridge. I spent two years as a Postdoctoral Research Fellow at the Keough-Naughton Institute for Irish Studies, University of Notre Dame, before joining the University of Oxford in 2026. I am a British Academy Early Career Fellow, and a Junior Research Fellow of Jesus College.

I am an historian of the United States and Ireland in the eighteenth and nineteenth centuries. My research to date has explored American immigration history, the history of Irish America and the American Civil War era. My first book, Republic, Empire, and Union: The Irish-American Press in the Era of Emancipation, 1840-1865, is a study of the Irish-American press in the decades before and during the Civil War, and the attitudes of Irish immigrants to imperialism, nationalism and enslavement. 

At Oxford, I will begin work on my second book, ‘Empire, Citizenship and Race: Mathew Carey and the Making of Irish America’, a major reconsideration of the emergence and consolidation of Irish America before the mass-immigration of the Famine generation, through a study of the career and legacy of Mathew Carey (1760-1838), the Catholic Irish-born publisher, philanthropist and humanitarian. The project uses Carey as a vantage point for exploring the Irish immigrant experience of the early-national and Jacksonian United States and his legacy and influence on subsequent generations of Irish immigrants to the United States. 

I'm also interested in the transnational and global history of the United States from the Revolution to the First World War, the history of Irish nationalism and the Irish diaspora, the intellectual history of American imperialism, ideas about nationhood and world order in the long nineteenth century, and the experience of religious minorities in the United States. 

My research has received several accolades, including the 2025 Society for the Study of Nineteenth-Century Ireland Annual Essay Prize; the 2023 Robert G. Crist Pennsylvania History Prize; Honorable Mention for the American Journalism Historians Association Margaret A. Blanchard Prize; a Kate B. and Hall J. Peterson Fellowship from the American Antiquarian Society; the William Reese Company Fellowship in American Bibliography from the Library Company of Philadelphia and the Malcolm and Mildred Freiberg Fellowship from the Massachusetts Historical Society. I have also served as a Research Associate of the McNeil Center for Early American Studies.