In 1937 Albert Brackmann , the Director-General of the Privy State Archives , wrote a letter of recommendation vouching for Posner 's archival abilities and popularity . Brackmann did this as a way to vouch for Posner under the early years of Hitler 's Nuremberg Laws . Posner had to take leave of his various positions and in 1937 he and his wife , Kathe , decided to emigrate to the United States . Posner traveled to the United States for two months in the Spring of 1938 . With the help of friends , Eugene Andersons of American University in Washington , Waldo Gifford Leland of the American Council of Learned Societies , Solon J. Buck of the National Archives , Posner began to position himself within the world of archives in America . At the National Archives he delivered the Good Friday 1938 lecture on the topic of German archival administration . However , the National Archives was reticent to offer employment to an alien . Posner then traveled to Harvard , Yale , the Rockefeller Foundation , and the Oberlander Trust looking for any type of employment . Since he was not successful , he eventually returned to Germany . In November 1938 , after Kristallnacht , he was arrested and sent to the Sachsenhausen Concentration Camp
Kristallnacht
Kristallnacht
Ernst Posner