YIVO, founded in 1925 in Wilno (Vilnius), is a center for scholarship on East European Jewish history, language, and culture. During the 1920s and early 1930s a network of YIVO affiliates was established across Europe and the Americas including one in New York, which became the institute's new home when YIVO was reestablished in 1940 by members of its board who had escaped from Nazi-occupied Europe. This is the first repository-level finding aid to the archives (over 1,400 collections) of the YIVO Institute for Jewish Research in New York. It includes a brief history of the institute and archives, descriptive entries on each collection, a detailed index of key words and subject headings, and information on the archive's basic services.