A Bridge Across the Ocean focuses on the relations between the United States and the Holy See from the First World War to the eve of the Second, through the combination of American, Italian, and Vatican sources.

More than an overall picture of the American and Vatican foreign policy during the first half of the twentieth century, the book analyses the U.S. Vatican rapprochement in a multifaceted way, considering both the international and the internal sphere. A Bridge Across the Ocean discusses the spread of anti-Catholicism in the United States during the first two decades of the twentieth century, and its repercussions on the American administrations' behaviour during and after the Versailles Conference, together with the changes that occurred in the Holy See's attitude toward the American church and the White House after the election of Pope Pius XI. Luca Castagna explores the convergence of the New Deal legislation with the church's social thought, and demonstrates how the partial U.S. Vatican rapprochement in 1939 resulted from Roosevelt and Pacelli's common aim to cooperate, as two of the most important and global moral powers in the struggle against Nazi-fascism.

A Bridge Across the Ocean deepens our understanding of American and church history during the first half of the twentieth Century, from the church-state relations to the identification of diplomatic strategies and priorities.