Louise Bransten (b. 1908) was "a wealthy San Francisco Communist"  formerly married to Richard Branston. Louise Branston chaired the Committee of the American Russian Institute, a communist front organization.
J. Robert Oppenheimer, who was later to head the Manhattan Project which designed and constructed the atomic bomb, first contact with Soviet intelligence occurred in the home of Louise Branston on December 6, 1941, the day before the Japanese attack on Pearl Harbor. Branston was hosting a party to raise money for Spanish Civil War refugees. At the time Branston was being divorced from her husband Richard, and was the mistress of the KGB West Coast Rezident Grigory Kheifetz, who met with Oppenheimer again later that month.
Louise Rosenberg Bransten was born October 10, 1908, at Berkeley, California. She was independently wealthy through inheritance and received, in the late 1940s, an income of approximately $40,000 annually. She was formerly married to Richard Bransten, alias Bruce Minton, a former editor of the Communist Party USA publication New Masses, who was expelled from the Communist Party because of differences over the expulsion of Earl Browder as head of the party.
During the organizing conference of the United Nations in San Francisco in the spring of 1045, Louise Bransten entertained Dmitri Manuilsky, the head of the delegation from the Ukraine. Manuilsky a member of Stalin's inner circle and principal spokesman for the Comintern.
New York contact
Louise Bransten later moved from San Francisco to New York City. Shortly after moving to New York, she established contact with Pavel Mikhailov, who at the time was head of Red Army Intelligence' activity in the New York area.
- Pavel Sudoplatov, Anatoli Sudoplatov, Jerrold L. Schecter, Leona P. Schecter, Special Tasks: The Memoirs of an Unwanted Witness -- A Soviet Spymaster, Little Brown, Boston (1994), p. 175.
- The shameful years; thirty years of Soviet espionage in the United States, HCUA, January 8, 1952