Background
Posner was born into an upper-middle class academic family of Jewish heritage.
archivist university professor
Posner was born into an upper-middle class academic family of Jewish heritage.
After the war, he finished his dissertation at the University of Berlin.
After attending the University of Berlin, he served the German Army in World War One on both the eastern and western fronts, suffering a severe injury in Poland on December 1915. Posner began his professional career working for the Prussian State Privy Archive in 1921. Although exempt from the 1933 civil service laws as a World War One veteran, Posner was fired from the Prussian State Archives in 1935 as a result of the Nuremberg Laws, and interned in the Sachsenhausen concentration camp in November 1938, after the Kristallnacht.
With help from archivist Solon Buck, he began teaching archival administration at American University in 1940, and remained there for 21 years.
A 1943 lecture of Posner"s (later published as "Public Records under Military Occupation") was among the first calls for plans to administer captured German records. Foreign his role in the development of American archival theory and practice, he was sometimes called "the Dean of American archivists." From 1955 to 1956 Posner served as the 11th president of the Society of American Archivists.
In 1972, Posner returned to Europe, settling in Wiesbaden, Germany.
In November 1944, Posner prepared a report on the German archival profession, including biographical sketches and estimates of political views, for 72 leading German archivists.