Entities
- National Bureau of Standards <Washington>
- Letter from: 23.1.1948, Washington
- National Portrait Gallery <London>
- Letter from: 3.7.1936, London (England)
- Neue Musikgesellschaft <Berlin>
- Letter from: 17.5.1920, Charlottenburg
- Letter from: 12.6.1920, Charlottenburg
- New York City Ballet
- Letter from: 31.12.1952, New York (N.Y.)
- New York Port Authority <New York>
- Letter from: 8.7.1947, New York
- New York University <New York>
- Letter from: 22.4.1942, New York (N.Y.)
- Letter from: 23.10.1950, Burlingame (Calif.)
- Nirona oder Frankonia Werke <Beierfeld>
- Letter from: 31.3.1915, Charlottenburg
- Letter from: 7.4.1915, Charlottenburg
- Letter from: 13.4.1915, Charlottenburg
- Letter from: 21.4.1915, Konitz (Germany)
- Norddeutscher Lloyd <Bremen>
- Letter from: 9.7.1924, Herrlingen (Germany)
- Novembergruppe
- Letter from: 2.7.1920, Charlottenburg
- Nurock Agency <New York>
- Letter from: 5.11.1947, San Francisco (Calif.)