The Electronic Numerical Integrator and Computer (ENIAC) is generally regarded as the first general-purpose electronic digital

computer. Funded by the U.S. Army for wartime calculations, particularly ballistic firing tables, it was built between 1943 and 1945 at the University of Pennsylvania's Moore School. The ENIAC project was led by John Mauchly and J. Presper Eckert and involved a large team of engineers who made crucial contributions to its design and construction. This team included Arthur Burks, who designed the multiplier, and Harry Huskey, who worked on the reader/printer.   

Once built, ENIAC was huge, occupying about 1,800 square feet (roughly 15 by 9 meters) and weighing around 30 tons and containing over 17,000 vacuum tubes. It was capable of running a ballistics trajectory, a calculation that would take a human using a desk calculator between 20 and 40 hours in approximately 30 seconds. This however required ENIAC to be programmed and the names of the programmers were unknown.

The Missing Programmers

It was as an undergraduate taking computer science courses at Harvard that Kathy Klieman noticed that all the credit for ENIAC was given to the engineers, all men, who built it, something that I Programmer's own account, Eckert & Mauchley and ENIAC, was initially guilty of. But for a computer to do anything useful it needs programmers and for many years their names had never been recorded. Having seen women in the photos of ENIAC, Kliemanwanted to find out their identities she went to the Computer History Museum where she was told the women were "just models" who were included in the photos "to make the machines look good"! Indeed the women in this photo were regarded as functioning as “refrigerator models”, a reference to 1950s TV commercials for home appliances, in which smiling female models in high heels would open refrigerator doors.

Klieman disagreed because the very same women appeared in other photos of ENIAC where it looked as though they knew exactly what they were doing. 

Having contacted the University of Pennsylvania, she was invited to ENIAC's 40th Anniversary where she met four of the women, Jean Jennings, Kathleen McNulty, Betty Holberton Snyder and Marlyn Wescoff, and learned the names of the other two, Frances Bilas and Ruth Lichterman, and started to hear their stories.