How did Irish and American diplomacy operate in Washington DC and Dublin during the 1930s era of economic depression, rising fascism and Nazism? How did the Anglo-American relationship affect American-Irish diplomatic relations? Why and how did Éamon de Valera and Franklin D. Roosevelt move their countries towards neutrality in 1939? This first comprehensive history of American and Irish diplomacy during the 1930s focuses on formal and informal diplomacy, examining all aspects of diplomatic life to explain the relationship between the two administrations from 1932 to 1939. Bernadette Whelan reveals how diplomats worked on behalf of their governments to implement Franklin D. Roosevelt and Éamon de Valera's foreign policies - particularly when Éamon de Valera believed in the existence of a 'special' transatlantic relationship but Franklin D. Roosevelt increasingly favoured a strong relationship with Britain. Drawing on a wide range of under-used sources, this is a major new contribution to the history of American and Irish diplomacy and revises our understanding of the importance of Ireland to a US administration.