In the first half of the twentieth century, mathematics was a highly unusual path of study for a young woman. It was expected that should she be able to attend college, she would go on to become a teacher or nurse, or enter some other traditionally female profession. Even if a woman opted to study something non-traditional like mathematics, it was unlikely that she would find a job in field. With the onset of WWII, the deployment of young men opened the door for bright, educated women to enter male-dominated fields.

Such was the case for the six women of the ENIAC project — women whose job titles literally read “computers”. As part of their work with the ENIAC project, these women programmed the first electronic digital computer. In doing so, they left an indelible mark on the history of computer programming.

In 1945, the Army decided to fund an experiment that they hoped would result in the world’s first operational electronic digital computer. It’s original purpose would be to calculate artillery ballistics. The result was the Electronic Numerical Integrator and Computer (ENIAC), which was an absolutely massive machine. Standing 8 feet high and covering 1800 square feet, the ENIAC was a sight to behold. In addition to its imposing presence, the ENIAC was also an overwhelmingly intricate machine, comprised of 5,000,000 soldered joints, 70,000 resistors, 10,000 capacitors, 6,000 manual switches and 1,500 relays. If they were going to hire people to program this thing, the Army was going to need the very best.

During the war, there were more than 80 women working as “computers” for the Army, calculating differential equations and ballistic trajectories by hand. It wasn’t long before these women gained a reputation for being not only as capable as their male counterparts, but in some cases, superior to their male counterparts. As such, when the army began selecting people to work with the ENIAC, they looked to these women. In the end, six women were hired: Kathleen McNulty, Mauchly Antonelli, Jean Jennings Bartik, Frances Snyder Holberton, Marlyn Wescoff Meltzer, Frances Bilas Spence, and Ruth Lichterman Teitelbaum.

The ENIAC was set up at the University of Pennsylvania’s Moore School of Electrical Engineering, and the women were instructed to calculate a difficult ballistics trajectory. Programming was very different in the forties. The women had no programming language or manuals to follow; instead, they had to figure out how to manually program the ENIAC, physically putting the data into the machine by using thousands of switches, dozens of cables, and multiple trays. This was the reason the women were known as “computers” as opposed to programmers.

The women worked in three teams of two to program the ENIAC to run its first trajectory. Marilyn and Ruth worked on the complex calculations using analogue calculators. Frances and Kathleen were responsible for working with the Differential Analyzer, and Jean and Betty led the group, directing the programming and working with the Master Programmer.

The women succeeded in getting the ENIAC to run the requested ballistics trajectory, and on February 14th 1946, the ENIAC was introduced to the world during a public demonstration. During the demonstration, the ENIAC ran the programmed trajectory, and both the public and the press were fascinated.

In 1947, the ENIAC was turned into the world’s first stored computer. This means that the women of the ENIAC project were the only ones to program the ENIAC at the machine level. Despite their incredible achievements with the ENIAC, the story of these 6 incredible female “computers” went almost completely ignored by history for roughly half a century. In fact, their stories were virtually lost until the 1980s when a young programmer named Kathy Kleiman rediscovered these women and began conducting archival research to put together their stories. She also began to apply for awards on their behalf, finally bringing their achievements into the spotlight and assuring their well-deserved place in computer history.

References include: Witi Museum,,, ©The Heroine Collective 2015 – Present, All Rights Reserved.
Amber Karlins

Written by Amber Karlins

Amber works as a professor in Florida, teaching writing, literature, and theatre. Her first book, a work of creative non-fiction, was published in 2011. She also enjoys academic writing and has published papers in such places as the African American National Biography and the Journal for the Society of Armenian Studies.
Unidentified U.S. Army photographer

Image by Unidentified U.S. Army photographer

(ARL Technical Library) [Public domain], via Wikimedia Commons