This recent translation of Luca Castagna's 2011 book (Un ponte oltre l'oceano) fills a critical lacuna for Anglophone scholars of US Catholicism. The author follows the transatlantic trajectory of Gerald Fogarty and Peter D'Agostino, and the volume even includes an insightful foreword by the former. Castagna assembles a wealth of archival evidence to demonstrate how pragmatic collaboration between Eugenio Pacelli (Pius xii) and Franklin D. Roosevelt yielded the ‘first signs of a thaw’ (p. 166) in diplomatic relations between the Holy See and the White House. The book draws from an impressive array of sources, including the Archives of the Catholic University of America, the Vatican Secret Archives, the National Archives, Roosevelt's Presidential Library and various Italian national collections. In particular, Castagna's command of woefully neglected Italian documents marks the work's most significant contribution to American Catholic transatlantic scholarship. The book traces the complicated history of US-Vatican diplomacy from the presidency of John Adams through the postbellum crisis of 1867, the Americanist-Modernist controversies, and the peace policy tensions between Benedict xv and Woodrow Wilson. This diligent narrative forms a preamble to the introduction of key events and figures that facilitated a remarkable diplomatic ‘thaw’ after World War I, one that had seemed impossible after a surge of anti-Catholicism surrounding Al Smith's failed presidential campaign. The final chapters outline the complex history of collaboration between Roosevelt and Francis Cardinal Spellman, Joseph P. Kennedy (father of John F. Kennedy) and, most especially, George Cardinal Mundelein. This study further illumines the often-ignored American dimension of Pacelli's controversial legacy with Fascism. Castagna's fine work not only invites but also practically demands a subsequent history of the post-World War II ‘thaw’ itself, one that examines US-Vatican anti-Communist collaboration from Pius xii to John Paul ii and the establishment of formal diplomatic relations with the Holy See in 1984.