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"The Amazing" GRACE HOPPER


Grace Hopper (1906-1992) was a pioneer in computer programming who worked on the Harvard Mark I, the world’s first programmable computer. She invented the first compiler (code translator) for a computer programming language. Her work laid the groundwork for the development of COBOL, one of the first high-level programming languages. Hopper even popularized the term “bug” for a computer glitch after she physically removed a moth from the Harvard Mark II

Hopper, born Grace Brewster Murray, was from a prosperous Manhattan family. Her father was an insurance executive, and her mother was a mathematician. She went to Vassar for a degree in math and physics and completed her Ph.D. in mathematics at Yale. Hopper’s career began in academia. She married Vincent Hopper, a comparative literature professor, and became a math professor at Vassar. After a few years, however, Hopper took a partial leave to concentrate on her own mathematics studies.

It was a time of change for the country as well. The U.S. entered World War II in December 1941, after the bombing of Pearl Harbor. Then 36 years old, Hopper joined the U.S. Navy, leaving Vassar for good and divorcing her husband. As Hopper said in a speech recorded in the documentary “The Queen of Code,” “‘41 was Pearl Harbor. The world was in a very, very critical state. Everybody in the country tried to do something for that war effort.” In 1944, she graduated first in her class from the Naval Reserve Midshipmen’s School at Smith College.

Although Hopper, now a lieutenant, had long wanted to be in the Navy, she was underweight and too old to serve. She was instead assigned to the Bureau of Ships Computation Project at Harvard University where she worked alongside Howard Aiken, who designed the Harvard Mark I computer. The Mark I was fully functional during the war and played a crucial role in the Manhattan Project. By 1945, the Mark I was the world’s most easily programmable computer.

Hopper's Moth in the Computer, the original computer "bug"


Meanwhile, another computer was being built in secret at the University of Pennsylvania. Unlike Mark I, which used punched paper inputs, the Electronic Numerical Integrator And Computer (ENIAC) was electronic and could execute five thousand commands per second to Mark I’s three commands per second. However, the Mark I had the edge, largely thanks to Hopper: the Mark I was easily programmable, whereas reprogramming ENIAC could take a whole day.

Hopper soon realized that electronics were the way of the future. In 1949, Hopper joined the team that was developing UNIVAC I, which was designed by the inventors of ENIAC. Unlike ENIAC and Mark I, UNIVAC (Universal Automatic Computer) was designed specifically for business and commercial use, but it was also used to help tabulate the 1950 U.S. Census. It was while working on the UNIVAC that Hopper created the first compiler, which translates code written in one programming language into another language. This was an extremely important breakthrough in coding, because it allowed people to translate human language into something that can instruct a computer.

"What I was after in beginning English language was to bring another whole group of people able to use the computer easily. The people that used English, not symbols. It was my own understanding of the different kinds of people, and I knew darn well most people didn’t like symbols. And you had to give them something else to work with, and obviously the next-best thing was English" (from an Oral History with Grace Hopper).

This work fed into the development of COBOL, which became a dominant programming language for businesses for the rest of the 20th century.



Wikicommons, Uploaded by Daderot

Hopper returned to the Navy in the late-1960’s. She was promoted to the rank of captain and later rear admiral. In celebration of her retirement and long career, Hopper was rewarded the Defense Distinguished Service Medal in 1986. At the time of her retirement, Hopper was 79, the oldest active duty commissioned officer in the U.S. In accordance with her hard-working nature, Hopper then became a senior consultant to Digital Equipment Corporation, serving mostly as a goodwill ambassador and speaking about the computer science field. Hopper held this position until her death in 1992.

Grace Hopper’s impact has been widely felt in the development of modern programming and in the field of technology. She is often referred to as the “queen of code,” “mother of COBOL,” and “amazing Grace.”

Julia Chen

First Published 2/25/2015


Do Your Own Research




Howard H. Aiken and Grace M. Hopper, "The automatic sequence controlled calculator — I," Electrical Engineering, 65/8-9, (Aug.-Sept. 1946): 384-391.

Grace Murray Hopper, “The Education of a Computer,” ACM ’52: Proceedings of the 1952 ACM national Meeting (Pittsburg, 1952), 243-249.

Grace Hopper, Oral History (1980)


Kurt Beyer, Grace Hopper and the Invention of the Information Age (Cambridge, MA: MIT Press, 2009).

Klint Finley, “Tech Time Warp of the Week: Watch Grace Hopper, the Queen of Software, Crack Jokes with Letterman,” Wired, October 10, 2014.

Walter Isaacson, “Grace Hopper, computing pioneer,” Harvard Gazette, December 3, 2014.

Gillian Jacobs, “The Queen of Code,” FiveThirtyEight Signals, ESPN Films.

Molly Lambert, “The Difference Machine: Ada Lovelace, Grace Hopper, and Women in Tech,” Grantland, January 29, 2015.

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