[2] His mother was born in Kemnath in the Upper Palatinate region of Bavaria and emigrated to Milwaukee in 1882 at age 14; Muench's parents married in 1888.

The archbishop of Milwaukee granted Muench permission to remain in Europe to study at University of Leuven (Belgium), Cambridge, Oxford, the London School of Economics, the Collège de France, and the Sorbonne.

[3] On August 10, 1935, Pope Pius XI appointed Muench the third bishop of the Diocese of Fargo, North Dakota; he was consecrated on October 15, 1935, and installed on November 6, 1935.

[5] In a meeting with the pope, Stritch recommended Muench for the role of apostolic visitor in Germany, because of his "sympathy" for the "suffering of the German people".

[13] One World appeared in both religious and secular publications alongside statements denying Germans' complicity in the Holocaust, especially the concept of collective guilt.

[14] According to Brown-Fleming, Muench's sympathies in his writing matched his actions as one of the most active participants in the Vatican's "postwar clemency campaign on behalf of convicted war criminals".

[19] In a 1948 letter to Carl Zietlow, a Minnesotan Protestant pastor of the NCCJ, Muench described the organization as unneeded because: "regarding anti-Semitism" he had "found very little of it".

[20] According to Phayer, for Muench as well as Pius XII, the "priority was not the survivors of the Holocaust, but the situation of the German Catholic refugees in Eastern Europe who had been driven from their homes at the end of the war.

[22] In February 1950, Pius XII instructed Muench to write a letter in support of clemency for some convicted German war criminals to General Thomas Hardy, the head of the U.S. Army European Command, who had the final word on all clemency decisions; with his new appointment as papal regent, Muench was to speak as a direct representative of the pope.

[23] In his diary, Muench made it clear that he viewed as "questionable" the sentences of war criminals who had not been directly involved in medical experimentation or other extreme acts at concentration camps or the deportation of people for slave labor.

[24] Prior to this, Muench had frequently become involved in individual clemency cases, but took care not to attract undue attention or publicity to the Vatican.

[21][31] Muench's role as apostolic visitor was upgraded to nuncio when the Allied High Commission permitted the Federal Republic to form an independent foreign affairs ministry in March 1951.

[34] The reports spoke not only of the immediate, material needs of German Catholics, but also of the spread of communism, a fear shared by Muench and Pius XII, and the subject of another 1954 audience between the two.

[34] Muench mourned the death of Pius XII in October 1958, telling friends that the pope "treated him with the affection and love of a father to his son".

[34] The correspondence between Muench and Pius XII focused almost exclusively on the various opinions shared by the two men, often with great levity, but rarely touched on the issues of anti-Semitism, the Holocaust, the wartime relationship between the church and Nazi Germany, and the situation of the postwar Jewry.

This makes them one of a very few collections of papers from German, American, or Vatican Catholic dignitaries of that time period that are "fully accessible to historians".

[41] Altogether, the papers weigh over 2,500 pounds, including those Muench transferred directly from Bad Godesberg to Fargo prior to moving to Rome.

[11] In addition, Muench received approximately 100 letters from U.S. Catholics and military government officials speaking frankly on taboo topics, such as anti-Semitism, the Holocaust, and its survivors.

[45] For example, when Muench encountered difficulty in 1946 in easing travel restrictions on members of the clergy, he wrote in his diary that the problem was due to "Jews in control [of the] Public Safety [division]".

[46] Similarly, Muench referred to Franz Cueppers, a Frankfurt banker convicted of conducting illegal foreign exchange as a "victim of Jewish lawyers".

[47] A recurring point of interest for Muench were what he referred to as "Thirty-Niners": Jews who had fled Germany in 1933 or 1934, received United States citizenship in 1939, and then enlisted in the U.S. Armed Forces—Muench believed—"to wreak their vengeance in every way possible on the defeated foe".

[45] Muench's writings often characterized Jews generally, and Jewish displaced persons specifically, to be "greedy, wilfully destructive, sexual predators, thieves, and anarchists involved in leftist activities".

[48] Prof. Michael Ott of Grand Valley State University calls the work a "critical contribution to the growing research on the question of the Roman Catholic Church's policies and actions with regard to the Holocaust during World War II".