Klara Dan von Neumann

Klára Dán von Neumann (née Dán; 18 August 1911 – 10 November 1963) was a Hungarian-American mathematician, self-taught engineer and computer scientist, noted as one of the first computer programmers. She was the first woman to execute modern-style code on a computer.

Work After their wedding, Dán and John von Neumann immigrated to the United States, where he held a professorship at Princeton University. Upon immigration, Dán listed her profession as "housewife". At this time, she was sharing an office with Adele Goldstine. Dán also enrolled in calculus at Princeton in 1947. This work was entirely novel, a feat that had never been completed before. Dán scored the job, however, due to the belief at the time that programming was menial work, similar to human computing, a job commonly held by women. For decades after this, society would devalue the work of programming, which ultimately allowed women to be a large part of the workforce. She trained a group of people drawn from the Manhattan Project to store programs as binary code. She worked for 32 days on the project, where she saw through and checked the final code. and later edited and published by Yale University Press as The Computer and the Brain. She also wrote an unpublished memoir entitled A Grasshopper in Very Tall Grass. podcast.

Personal life and death Dán met her first husband, Ferenc Engel, at one of her parents' parties. Throughout her marriage to Rapoch, Dán maintained contact with John von Neumann.

In 1938, after von Neumann went through a divorce himself, Dán divorced Rapoch and married von Neumann.

On August 30, 1939, with the start of World War II looming, Dán traveled back to Budapest by boat to convince her parents and in-laws to leave the country. He died in 1957.

In 1958, a year after von Neumann's death, Dán married her fourth husband, oceanographer and physicist Carl Eckart, and moved to La Jolla, California.

Over the course of her four marriages, Dán never had children of her own. Her stepdaughter, Marina von Neumann Whitman (March 6 1935 – May 20 2025), was two years old when Dán and von Neumann married, and grew up to become a prominent economist, automobile executive, and professor of business administration and public policy.

In 1963, Dán drove from her La Jolla home to the beach, where she walked into the surf and drowned. The San Diego coroner's office listed her death as a suicide. She was 52 years old.