Vishniac’s sister-in-law had immigrated to the U.S. in the 1930s and was living in New York when he was interned in France. Along with several of Vishniac’s family members and friends, she wrote numerous letters requesting help in procuring visas for the Vishniac family from U.S. immigration authorities and the State Department. Her letter also mentions Vishniac’s assignments for the Jewish Joint Distribution Committee (JDC) and his pioneering work in photomicroscopy, to verify his professional credentials and employment prospects as a photographer. Ultimately, Claire Holt’s support was crucial to the Vishniac family’s acquisition of American visas.