Laurence Duggan (1905–December 20, 1948), was head of the South American desk at the United States Department of State during World War II. In 1948, Duggan fell to his death from the window of his office in New York, ten days after being questioned by the Federal Bureau of Investigation about whether he had had contacts with Soviet intelligence. For many years he was widely thought to be an innocent and loyal public servant who was driven to suicide by unfounded McCarthy era accusations. Statement of Tom Clark, Attorney General of the United States (December 24,1948): "The FBI investigation has produced no evidence of Mr. Duggan's connection with the Communist Party or with any other espionage activity. The evidence at the time indicated that Mr. Duggan was a loyal employee of the United States Government. In the 1990s, evidence from decrypted Soviet telegrams was revealed which indicated he had engaged in espionage for the Soviet Union.
Duggan studied at the Phillips Exeter Academy and Harvard University, before graduating in 1927. He worked for a number of years at the State Department—nine of those said years as head of the Latin American Division, and four of those as adviser on political relations. Starting in 1946, he was president of the Institute of International Education, which provided for a flow of exchange students between the United States and several other countries.
Duggan was recruited by journalist Hede Massing as a Soviet spy in the mid-1930s. Duggan told the FBI that Henry Collins of the Ware group had also tried unsuccessfully to recruit him. Duggan was a close friend of Noel Field of the State Department. The GRU had also tried to recruit him through Frederick Field.
Duggan provided Soviet intelligence with confidential diplomatic cables, including from American Ambassador William Bullitt. He was a source for the Soviets until he resigned from the State Department in 1944. He later served with the United Nations Relief and Rehabilitation Administration (UNRRA).
According to Boris Bazarov, Duggan told his Soviet handlers: "The only thing which kept him at his hateful job in the State Department where he did not get out of his tuxedo for two weeks, every night attending a reception, was the idea of being useful for our cause."
On December 15, 1948, Duggan fell to his death from his office at the Institute of International Education, located on the 16th floor of a building in midtown Manhattan. A few days later, the New York Police Department made public the result of its investigation, which concluded: "Mr. Duggan either accidentally fell or jumped." He left a wife, Helen Boyd Duggan, and four children.
The Venona project succeeded in decrypting some Soviet intelligence cables that had been intercepted in the mid-1940s. The code name used for Laurence Duggan in the decrypted transcripts is "Frank". He is referenced in the following Venona decryptions, which provided information to the Soviets about Anglo-American plans for invading Italy during World War II:
- 1025, 1035–1936, KGB New York to Moscow, June 30, 1943
- 380 KGB New York to Moscow, March 20, 1944
- 744, 746 KGB New York to Moscow, May 24, 1944
- 916 KGB New York to Moscow, June 17, 1944
- 1015 KGB New York to Moscow, to Victor [Fitin], July 22, 1944
- 1114 KGB New York to Moscow, August 4, 1944
- 1251 KGB New York to Moscow, September 2, 1944
- 1613 KGB New York to Moscow, November 18, 1944
- 1636 KGB New York to Moscow, November 21, 1944
- "The Man in the Window", Time, January 3, 1949.
- Haynes, John Earl; Klehr, Harvey (2000). Venona: Decoding Soviet Espionage in America. Yale University Press. pp. 201–204. ISBN 0-300-08462-5. More info
- The spy who made McCarthy, New evidence reveals that the unwitting architect of the McCarthy witch-hunts was a Soviet agent. Julian Borger on the strange case of Samuel Dickstein, The Guardian, Tuesday 26 January 1999. 
- National Security Agency Venona transcript, September 2, 1944
- "Lawrence Duggan 1905-1948. In Memoriam", Stamford, CT Overbrook Press (1949)
- Vassiliev, Alexander (2003), Alexander Vassiliev’s Notes on Anatoly Gorsky’s December 1948 Memo on Compromised American Sources and Networks, retrieved 2012-04-21
- Visit the Cold War International History Project (CWIHP) for the full text of Alexander Vassiliev's Notebooks containing more information on Duggan's involvement in Soviet espionage.