Erwin Taenzer and Ilse Taenzer received the letters from their mother, Bertha Taenzer from1937 to 1943. The letters to Ilse written after 1939 were forwarded to her sister, Irene, in Budapest, then on to Ilse in London. Erwin Taenzer acquired the complete set of letters after Ilse's death in 1979. He donated the collection to the United States Holocaust Memorial Museum in July1997.