Eilenberg's identity papers, passports, and other travel and legal documents, document his early life and travels (Box 1, Folder 2). Along with war-era documents attesting to his birth date in the absence of a birth certificate and a copy of his marriage license in 1960, are copies of Eilenberg's Polish passports (his later U.S. Passports are missing), visas, and official travel papers, which document his travels through 1930s Europe. Stamps on travel documents for entry into Nazi Germany provide vivid testimony to the Europe that Eilenberg fled in 1939. There are various identity cards, documents, and correspondence relating to Eilenberg's work for the Division of War Research at Columbia in the 1940s, under the auspices of the U.S. Office of Scientific Research and Development; among this material is official correspondence about the possibility of him doing consulting work as a mathematician in an "active war theater." Also there appears to be a dated 1913 copy of Eilenberg's Polish Birth Certificate.