The article examines the exchanges between the Vatican Secretary of State and the Vatican’s diplomatic post in Washington, DC, during the time of the presidential election of 1928 to show the different players and roles in the debate about the role of Catholics in American politics. These newly-available documents demonstrate and confirm Peter D’Agostino’s call for the need for a more transnational approach to the history of American Catholicism. The relationship between “American exceptionalism” and American Catholic history needs to be investigated with greater consideration for Roman perspectives and Roman institutional influence on the American Catholic experience. This research highlights, in Robert Orsi’s words, an “ambiguity and ambivalence” of American Catholic identity that has methodological consequences for historians of Catholicism as it takes a global turn.