Clara and Wilhelm Dreyfuss wrote the letters to Clara's sister and her husband, Recha and Wilhelm Reutlinger. Bertha and Leo, children of Clara and Wilhelm Dreyfuss, were hidden by Œuvre de secours aux enfants (France) (OSE) in France. Later the children were smuggled to Switzerland, and after World War II, the orphaned children emigrated to the United States. They were brought up by Recha Reitlinger. Recha Reutlinger gave the letters to Bertha Dreyfuss (now Bertha Strauss). She donated the collection to the United States Holocaust Memorial Museum Archives in June 2003.