Source: Timeline
Feb. 10, 1939 Pope Pius XI dies.
Mar. 1, 1939 Eugenio Pacelli is elected Pope and takes the papal name Pius XII.
Mar. 3, 1939 An American diplomat writes from Germany about the newly elected Pope, summarizing views that Pacelli expressed to him privately in 1937 about Nazi Germany.
Concerning Hitler and Nazism, Consul A. Klieforth wrote: “He said that he opposed unalterably every compromise with National Socialism. He regarded Hitler not only as an untrustworthy scoundrel but as a fundamentally wicked person...”
Source: Rychlak, Hitler, 2010, pp. 401-402, reprinting communiqué of March 3, 1939 from Klieforth to Jay Pierrepont Moffat, Chief of the Division of European Affairs, US Department of State.
Mar. 12, 1939 Eugenio Pacelli is crowned as Pope Pius XII.