United States Holocaust Memorial Museum Collection, Gift of Margot Loewenberg The John and Margot Loewenberg papers were donated to the United States Holocaust Memorial Museum through two separate donations in 1994 by Margot Loewenberg. These two donations were given different accession numbers: 1995.21 and 1995.A.0265. These papers have since been merged together, and can be located under one accession number: 1995.A.0265.