German-born émigré economist Dr. Otto Nathan, lectured at Vassar on "The Economies of Disarmament."  Fleeing Nazi Germany in 1933, Nathan settled briefly at Princeton, where a life-long friendship with physicist and fellow émigré Albert Einstein began.  At Einstein’s death in 1955, he was named sole executor of the Einstein estate and joint trustee of Einstein’s literary property, which he trebled in size and which went, in 1982, to the Hebrew University in Jerusalem.

Otto Nathan taught at Vassar from 1942 until 1945.  One of his students, Adele Gabel Bergreen ’44 and her husband, Morris, became close friends of Nathan’s in the 1950s, and he eventually gave them his personal collection of letters, photographs, books and other items belonging to Einstein.  These materials were given to the college by Mrs. Bergreen, and they constitute the Morris and Adele Bergreen Einstein Collection at Vassar College.