An NKVD foreign intelligence pseudonym which appeared in the notes on KGB foreign intelligence files taken in the mid-1990s by the former KGB officer and journalist Alexander Vassiliev. This pseudonym was identified by Vassiliev as belonging to the U.S. State Department official Laurence Duggan. It appeared from 1935 to August 1944.

In one Venona partially decrypted NKGB cable sent from New York to Moscow on May 29, 1943, “19th” appears as a source of diplomatic information. When this cable was released in 1996, the pseudonym “19th” was not identified.