What “first” can and cannot mean
The title uses the word “assisted”, while the field’s usual name is computer-aided design. Both forms appear in older writing and refer to the same idea. The more important correction is that no single program can be named as the first. In the late 1950s and 1960s, several groups in universities, aerospace firms, automakers and computer companies built drafting and design programs more or less in parallel, often without knowing the details of each other’s work. Which one counts as first depends on how strictly you define “CAD software”, and historians do not agree on one answer.
Three kinds of early project
It helps to separate the early efforts by purpose.
Research prototypes. These explored what was possible. The best known is Sketchpad, a doctoral project by Ivan Sutherland at the Massachusetts Institute of Technology, completed in the early 1960s. It let a user draw on a display with a light pen, and it recorded the drawing as structured data with geometric relationships, not as a mere picture. It was not designed for production use, but it gave later developers a vocabulary of ideas.
In-house industrial systems. Large manufacturers built systems for their own needs. General Motors worked with IBM in the early 1960s on a design system for automobiles, and aerospace companies developed tools for drawing and for describing curved surfaces. These projects were closed, expensive and tied to specific mainframe computers, so their influence spread mostly through the engineers who worked on them and through papers and conferences.
Commercial products. By the late 1960s and into the 1970s, some firms were selling drafting systems to other companies. Part of this lineage traces to in-house software that proved useful enough to offer outside, and part to new companies formed by engineers who had worked on earlier projects.
Other names often mentioned
Because the history is spread across many organizations, a few other names come up repeatedly in accounts of the period.
- A researcher at GE named Patrick Hanratty is often credited with early work on programs connecting geometry to numerical control machining in the late 1950s, and later with software that grew into commercial CAD products. His role is widely acknowledged, though accounts differ on which specific program was the first of its kind.
- A drafting machine developed by a company called Itek around the early 1960s combined a computer with a display, and is sometimes cited as an early drafting system.
- At Boeing, a researcher is often credited with popularizing the phrase computer graphics for early figures and illustrations around 1960.
- Researchers in France, working at automakers, developed the mathematics of curves and surfaces that later underlay many CAD programs.
These bullet points are summaries of widely repeated accounts, not a ranking. If you read a source that names one person as the inventor of CAD, it is probably compressing a more complicated story.
Why the programs differed so much
Early CAD was shaped by hardware limits. A display in the early 1960s could be a costly vector tube, one of the early CRT displays, driven directly by a large computer, with no way to fill a shape with color. Memory was small, and a drawing had to be stored in a way that could be redrawn quickly. For these reasons the programs were less like a modern drawing application and more like a toolkit for a specialist: the user selected commands, pointed, and the computer calculated the geometry.
Programs also differed in what they aimed to do. Some were drafting tools that produced a precise two-dimensional drawing. Others were about describing a three-dimensional surface, such as a car body, from a handful of control curves. Some were closer to manufacturing support, producing instructions for machines. Putting all of these under one heading “CAD” is a convenience of later writing.
The role of definitions
If CAD means any program that helps a person make a technical drawing, the starting point might be drawing programs that output to a plotter. If it requires interactive drawing on a screen, the starting point moves toward the early 1960s research systems. If it requires a commercial product that a customer could buy, the answer shifts again to the late 1960s or 1970s. None of these definitions is wrong, and each produces a different “first”.
What can be said with confidence
Some points are well established:
- Interactive graphics for design was an active research area among the 1960s computers that had displays at all.
- Large manufacturers, especially in the automotive and aerospace sectors, were developing and using their own systems during that decade.
- Commercial CAD products existed by the 1970s and used minicomputers and graphics terminals.
- Desktop CAD on personal computers followed in the early 1980s.
Beyond that, the exact dates, authorship credits and sales claims found on websites vary and are sometimes repeated without a source. A careful reader should treat any very specific “first” with suspicion, and should look for several independent accounts before accepting it.
Why the question matters less than it seems
The practical legacy of the early programs lies in the ideas they established: a drawing is data, a change can propagate, a part can be reused, and a drawing can feed other processes. Those ideas appeared, in different forms, in several places at once. That pattern is typical in technology history, where the same need and similar hardware lead independent groups to similar solutions.