Before the machines: human computers
Before electronic machines, large calculations were done by teams of people, and these workers were called computers. Many were women, hired because the work was repetitive and wages were low. They calculated tables for astronomy, navigation, artillery, and engineering, often following carefully divided procedures.
This background matters because it shaped how the first electronic machines were staffed. When machines arrived, the people already trained in organized, accurate calculation were often the ones who moved over to them.
ENIAC and its programmers
One of the best-documented examples is ENIAC, built at the University of Pennsylvania during and just after World War II and publicly unveiled in 1946. It was used to compute artillery firing tables, among other tasks.
The designers focused on the hardware. The job of working out how to make the machine solve a particular problem fell to a group of women who had been recruited from the ranks of human computers. Six are usually named: Kay McNulty, Betty Jean Jennings, Betty Snyder, Marlyn Wescoff, Fran Bilas, and Ruth Lichterman. Others were also involved with the project.
There was no programming language or manual in the modern sense. The women studied wiring diagrams and the machine’s design, then set up each problem by connecting cables between units and adjusting switches. A new problem could mean extensive physical reconfiguration, and the team had to understand the machine in detail to find faults. They are often credited with developing methods for breaking a problem into steps that the machine could carry out, and for debugging at the level of circuits and logic.
The importance of the work was not always recognized. In the 1940s, writing the setup for a problem was commonly regarded as lower-status than designing the hardware. At the public demonstration, the women’s roles were mostly unmentioned. Photographs from the era sometimes show them without names, and for decades some were misidentified as models posing next to the machine. Their contributions were rediscovered by historians and interviewers, particularly from the 1980s onward.
ENIAC was later modified so that it could be controlled from stored instructions instead of rewiring for every problem, a step toward the stored-program concept, and some members of this group were involved in that work.
Other projects
ENIAC is not the whole picture.
- Harvard Mark I. Naval personnel, including Grace Hopper, prepared sequences of operations for this electromechanical machine in the 1940s.
- Wartime code breaking. At Bletchley Park in Britain, many women worked in the codebreaking effort, including as operators of machines. Details of this work stayed secret for decades after the war, which delayed recognition.
- Postwar commercial machines. As companies and universities bought computers, women worked as programmers, coders and operators on projects such as business and scientific systems, including some of the first commercial computers.
- Entrepreneurs. In 1962, Stephanie “Steve” Shirley founded a British software company that employed women programmers working from home, many of whom had left conventional jobs after having children.
Why the role was undervalued
In the early years, programming had no established career path. Managers often thought of it as a kind of clerical or translation task: once the engineers had defined the problem, someone had to “code” it. Because the hardware was the visible, expensive part, people who worked on it received most of the attention.
As the field matured, it became clear that software required deep skill. Programming gained prestige, and over time the profile of the workforce changed in many countries. In the United States, for instance, the share of women among computer science graduates rose into the 1980s and then fell, though the reasons are debated and varied by country. Historians point to a combination of factors, including hiring practices, marketing of home computers, and social expectations.
How we know what we know
Our knowledge of these women comes largely from later research. Oral history interviews, records from the projects, and documentary work have helped to recover names and roles. Some details remain uncertain: accounts of exact job titles, dates, and who did what vary between sources, and recollections given decades afterward may be imperfect.
For that reason it is wise to be careful with sweeping statements, such as saying that “women invented programming”. The evidence supports a more modest claim: women were among the earliest people to do the practical work of programming electronic machines, they did so under challenging conditions, and they were frequently underrecognized.
What this changes about the story
It is tempting to tell the history of the first computers as a story about machines and their inventors. Including the programmers changes the emphasis. A computer needs hardware, but it is useless until someone figures out how to make it do something. Seen that way, the programmers and operators were as essential as the circuit designers.
The same lesson applies beyond ENIAC. Many other early projects relied on staff who set up the machines, ran them, checked results, and wrote the first routines, and who were rarely named in press coverage. Looking for those names is one of the best ways to see early computing as it was: a collective effort.