Katherine Oppenheimer

Kitty joined the Communist Party through her husband Joseph Dallet and became involved in various activities, including serving as a 'literary agent' for the party.

Kitty planned to join the International Brigades in Spain but was prevented from doing so due to French government prohibitions and her husband's death.

Kitty left the Communist Party, later stating that she no longer believed in its international connections.

Katherine Puening was born in Recklinghausen, Germany.

Kitty moved to Pittsburgh, Pennsylvania, with her family, where she grew up in a privileged environment as the daughter of an engineer.

Kitty pursued her higher education, eventually enrolling in graduate studies at UCLA in 1939.

Kitty's first marriage was to musician Frank Ramseyer, which was annulled a few months later.

Kitty married Joseph Dallet, a communist organizer, who died in 1937 fighting in the Spanish Civil War.

Kitty married doctor Richard Harrison, whom she divorced in 1940 to marry J. Robert Oppenheimer.

Kitty married J. Robert Oppenheimer in Virginia City, Nevada, the day her divorce from Harrison was finalized.

Kitty was interviewed by the FBI, confirming details of her past association with the Communist Party.

Kitty testified multiple times during her husband's security clearance hearings, emphasizing her opposition to communism and minimizing Robert Oppenheimer's connections to the ideology.

Katherine Oppenheimer died in Panama City, Panama.

Katherine Vissering 'Kitty' Puening was born in Recklinghausen, Westphalia, Prussia, Germany, to Franz Puening and Käthe Vissering. She was their only child.

At the age of two, Kitty immigrated to the United States with her family aboard the SS Kaiser Wilhelm der Grosse. Her father, a metallurgical engineer, had secured employment with a steel company in Pittsburgh, and the family settled in the suburb of Aspinwall, Pennsylvania.

Kitty graduated from Aspinwall High School in June 1928. Following this, she enrolled at the University of Pittsburgh, studying mathematics, biology, and chemistry.

In March 1930, Kitty sailed to Europe, where she met Frank Ramseyer, an American music student in Paris. She returned to the United States on May 19, 1930.

After returning to the United States in August 1934, Kitty moved in with Joseph Dallet, a member of the Communist Party of America. They became common-law spouses and were deeply involved in communist activities.

Kitty and Joseph Dallet separated in June 1936. She then moved to live with her parents in Claygate, England, and worked as a German-to-English translator.

Joseph Dallet was killed in action on October 17, 1937, while fighting in the Spanish Civil War. Kitty had planned to join him but was delayed due to health issues.

Kitty married Richard Stewart Harrison, a medical doctor, on November 23, 1938. She had met him while enrolled at the University of Pennsylvania.

Although the exact date of her marriage to J. Robert Oppenheimer is not specified in the provided sources, it is known that she married him after her divorce from Harrison. Her son, Peter, was born on May 12, 1941.

Kitty and J. Robert Oppenheimer moved to Los Alamos, New Mexico, in March 1943, where Robert became the director of the Manhattan Project's Los Alamos Laboratory. Kitty worked as a lab technician under Louis Hempelmann and later hosted social gatherings for the community.

Kitty was called as a witness in her husband's security hearing by the Atomic Energy Commission. She firmly stood her ground, answering questions about her past communist affiliations and emphasizing her opposition to communism.

Kitty Oppenheimer died in Panama City, Panama, on October 27, 1972.