Grace Hopper And The Invention Of The Information Age (book)

Reviewed: Aug 2026

I'll be moving into my classroom at the brand new Grace Hopper Center in just a few weeks. To prepare for the transition, I thought I should spend a bit of time learning about our schools new namesake. This book was a great summary of computing history, as well as the life of Grace Hopper.

Here are a few facts that I'll be excited to share with my students this school year:

Hopper was one of the first programmers, and designed and wrote the operating instructions for the Harvard Mark I computer one of the first-ever general-purpose computers. I appreciated the quote from the operating instructions that said the entire process was "computed, designed, coded, babied, nursed, pleaded with, and mothered by Lt. (j.g.) Grace Murray Hopper, USNR."
- Most of this work was done to solve urgent math problems during World War II. One of those was the calculations for imposion forces that enabled the Manhattan Project - but Hopper and team were only given the math problems. They didn't know the application until after the war.
Part of the reason Hopper authored most of the reports from the Harvard team was that she was a big proponent of writing: For example, when she was a professor at Vassar: "When they came into my probability course, the first thing I did was give them a lecture on Sterling's formula and then ask them to write it up as an essay. I'd cover it with ink and I would get a rebellion because they were taking a math course, not an English course. Then I would explain it was no use trying to learn math unless they could communicate it with other people."
Part of Hopper's later success in bringing computing to a variety of business applications was that she studied a wide variety of topics. While she was a professor at Vassar, "Hopper audited courses in Astronomy, physics, chemistry, geology, biology, zoology, economics, architecture, philosophy, and the history of scientific thought. " She was also responsible for evolving Vassar's math department from purely theoretical math to a focus on applications.
Hopper spent a lot of her career in sales - having to convince folks to invest in the computing industry. Specifically, funders had trouble believing of the idea that computers could do more than calculate. In a 1953 "Plea for a budget" to her leadership at Remington Rand, Hopper first proposed the concept of data-driven decision making: "In any business or industry, a large quantity of information exists on paper. This information in random, unprocessed form is of little or no valuable to management as a basis for decision making. When information is organized and processed, it becomes intelligence effective. Management then relies on the ability to process information to be used in decision making. "
Hopper helped create the Association for Computing Machinery (ACM). And specifically was the head of "ACM's Nomenclature committee, where she helped define a common language for the industry as a whole." This part reminded me of how Jeff always talks about Freire's concept of "naming the world"
Throughout her career, Hopper fought against isolationist business practices and instead promoted sharing among the computing community, this was probably the first ever example of open source software. I liked this passage from the book "Hopper believed that the process of invention should not be confined to herself, her staff, or even her company. Information flowed smoothly between her team and other organizations, with Hopper serving as the conductor of invention rather than its dictator.” and I liked this quote from one specific proposal she wrote for the ACM "It is our earnest plea that we receive comments, both mild and violent, suggestions, and criticisms as soon as possible. "
Hopper was most proud of her role as a teacher
- "The most important thing I’ve accomplished, other than building the compiler, is training young people. They come to me, you know, and say, ‘Do you think we can do this?’ I say, ‘Try it.’ And, I back ‘em up. They need that. I keep track of them as they get older and I stir ‘em up at intervals so they don’t forget to take chances."
- I liked this line from the book: "Common sense would dictate that the most experienced programmers should be assigned to the most difficult tasks. But as Hopper glibly explained, young people did not know that they were supposed to fail. " (I tried to find a source for that quote, but I couldn't figure out where it came from. )
One way that Hopper promoted camaraderie with her crews during stressful working settings was through humor and practical jokes. The Smithsonian collection includes a "humor file" along with a very thorough table of contents that Hopper maintained. I like this drawing of computer bugs, including the "Kitchie Boo Boo Bug -He who goes around loosening relays": https://sova.si.edu/record/nmah.ac.0324/ref448

A few topics that will make good stories for in our CS classes:

Hopper's team invented the concept of subroutines, and she wrote about them in a cool paper called "The Education of a Computer". After describing the concept of subroutines she said "Thus, the completed program may be run as a unit whenever desired, and may itself be placed in the library as a more advanced subroutine." and explained how subroutines could build upon themselves to increase in complexity over time.
- I liked the last paragraph of this paper: "the computer is fully capable of remembering and acting upon any instructions once presented to it by the programmer. With some specialized knowledge of more advanced topics UNIAC at present has a well grounded mathematical education fully equivalent to that of a college sophomore - and it does not forget and does not make mistakes. It is hoped that its undergraduate course will be completed shortly and it will be accepted as a candidate for a graduate degree."
As part of developing FORTRAN, Hopper first introduced variables that have descriptive english names (vs register names). This was a point of contention during the development of COBOL, and Hopper fought strongly (and won) in support of english names
Hopper might have been one of the first software hackers. To make the Mark 1 run faster, "With their knowledge of hardware. Hopper and Block realize that a little bit of programming ingenuity could maximize the machine's processing power in the minimal number of drive shaft rotations. For instance, for an operation requiring 25 cycles, only five actually produced activity in the main bus of the machine. Hopper and Block began to embed in additional operations within instructions, making certain that the embedded codes did not adversely affect the primary operation in progress. For instance, printing commands could be implanted within a multiplication operation. Soon, it became standard practice to write programs that maximize the number of embedded instructions. As a result, processing time decreased by as much as 36%. Because of the relatively slow processing speed of mark, 136% could easily translate into weeks of saved runtime."
I knew this one already: the term "bug" in engineering predates Hopper, but her team found an actual bug in the relays of the Mark I and taped in their journal. They brought the term "bug" to computing, and coined the term "debugging"
The book has an interesting section about flow charts - Their invention is contested, but one story is that they were created by one of Hopper's collaborators, Betty Snyder Holberton.
Fun anecdote: Hopper got so used to thinking and writing code in octal instead of decimal that she said she would often have trouble balancing her checkbook at the end of the month because she would slip into octal addition and subtraction when balancing her accounts.