Grace Murray Hopper (1906-1992): A legacy of innovation and service

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Hopper believed that computers would someday be widely used and helped to make them more user friendly. (Courtesy of the Computer History Museum)

On Feb. 11, President Peter Salovey announced that he and the Yale Corporation had voted to change the name of Calhoun College, one of the university’s undergraduate residential colleges, to honor alumna Grace Murray Hopper. Grace Brewster Murray Hopper was a computer pioneer and naval officer. Read the story. Here is a look at Hopper’s life and legacy.

Grace Brewster Murray Hopper was a computer pioneer and naval officer. She received a master’s degree (1930) and a Ph.D. (1934) in mathematics from Yale. One of the first three modern “programmers,” Hopper is best known for her trailblazing contributions to the development of computer languages. Known as irreverent, sharp-tongued, and brilliant, she enjoyed long and influential careers in both the U.S. Navy and the private sector.  

The daughter of Walter Fletcher Murray (Yale B.A. 1894, Phi Beta Kappa) and Mary Campbell Van Horne, Grace Brewster Murray was born in 1906 in New York City. Her father owned an insurance company. She was educated in private schools, and the family summered in Wolfeboro, New Hampshire. In 1928 she graduated Phi Beta Kappa from Vassar College with degrees in mathematics and physics. In 1930 Hopper received her master’s degree in mathematics from Yale. In 1931 she began teaching mathematics at Vassar while pursuing her doctorate at Yale under computer pioneer Howard Engstrom. In 1934 she completed her Ph.D. in mathematics and mathematical physics from Yale. During a one-year sabbatical from Vassar, Hopper studied with the famous mathematician Richard Courant at New York University.

Hopper came of age at a time of unusual opportunity for women. A relatively high number of women were receiving doctorates in the 1920s and 1930s — numbers that would not be matched again until the 1980s.1 World War II also created opportunities for women to enter the workforce in greater numbers. Nonetheless, Hopper’s success in a male-dominated field and in male-dominated organizations, including the U.S. Navy, was exceptional.

After the bombing of Pearl Harbor and the United States’ entry into World War II, Hopper decided to join the war effort. She was initially rejected because of her age and diminutive size, but she persisted. Taking a leave of absence from Vassar, where she was an associate professor, Hopper joined the U.S. Naval Reserve (Women’s Reserve) in December 1943 and was assigned to the Bureau of Ships Computation Project at Harvard University. There she worked for Howard Aiken, another computer pioneer, who had developed the IBM Automatic Sequence Controlled Calculator, better known as the Mark I, one of the earliest electromechanical computers. One of the first three computer “programmers,” Hopper was responsible for programming the Mark I and punching machine instructions onto tape. She also wrote the 561-page user manual for the Mark I.

The close relationship between the American military and the early computer industry, nurtured first by World War II and then the Cold War, shaped Hopper’s career path. Hopper and her fellow officers in the Harvard lab worked on top-secret calculations essential to the war effort — computing rocket trajectories, creating range tables for new anti-aircraft guns, and calibrating minesweepers. In addition to their work for the Navy, Hopper and her colleagues also completed calculations for the army and “ran numbers” used by John von Neumann in developing the plutonium bomb dropped on Nagasaki, Japan.

After the war Hopper turned down a full professorship at Vassar in order to remain at Harvard, becoming a research fellow in engineering sciences and applied physics. During this time she helped develop the Mark II and Mark III computers as Harvard continued to receive funding contracts from the Navy. One evening in 1945 while working on the Mark II, Hopper and her colleagues encountered a problem. They took the machine apart and found a large moth. Although the term “bug” had been used by engineers since the 19th century to describe a mechanical malfunction, Hopper was the first to refer to a computer problem as a “bug” and to speak of “debugging” a computer.

In 1946 Hopper left active service when the Navy turned down her request for a regular commission because of her age. Shortly thereafter Hopper left Harvard when it became clear she would not be promoted or granted tenure. In 1949 she joined the Eckert-Mauchly Computer Corporation in Philadelphia as senior mathematician. The company, which was soon acquired by Remington Rand, had developed the first electronic computer (the ENIAC) under army contracts.

In Philadelphia Hopper undertook some of her most influential work. As head programmer for Remington Rand, she worked on the UNIVAC I (Universal Automatic Computer). In 1952 her programming team developed the first computer language “compiler” called A-0. Compilers translated mathematical code into machine-readable binary code, and they would eventually make it possible to write programs for multiple computers rather than a single machine. Next her team developed Flow-Matic, the first programming language to use English-like commands. Unlike earlier computer languages such as FORTRAN, which used mathematical symbols, Flow-Matic used regular English words. Hopper felt that data processors, who were not typically mathematicians or engineers, would be more comfortable using word-based languages. In a 1980 interview she explained, “What I was after in beginning English language [programming] was to bring another whole group of people able to use the computer easily … I kept calling for more user friendly languages. Most of the stuff we get from academicians, computer science people, is in no way adapted to people.”2

When she retired as a rear admiral at age 79, Hopper was the oldest serving officer in the U.S. Armed Forces. (Image from public domain)

As the number of computer languages proliferated, the need for a standardized language for business purposes grew. In 1959 COBOL (short for “common business-oriented language”) was introduced as the first standardized general business computer language. Although many people contributed to the “invention” of COBOL, Hopper promoted the language and its adoption by both military and private-sector users. Throughout the 1960s she led efforts to develop compilers for COBOL. Her biographer Kurt Beyer calls her “the person most responsible for the success of COBOL during the 1960s.” Her influence was significant; by the 1970s COBOL was the “most extensively used computer language” in the world.3

Throughout her career in the private sector, Hopper had remained a Navy reservist. In 1966 age restrictions forced her to retire from the Navy as a commander. She later called it “the saddest day of my life.”4 Seven months later, however, at the age of 60, she was recalled to active service. Increasing operations in Southeast Asia were taxing the Navy’s capacities, and her help was needed to standardize the Navy’s multiple computer languages. Nicknamed “Amazing Grace” by her subordinates, Hopper remained on active duty for 19 years. She retired from UNIVAC, a division of Sperry Rand, in 1972.

Hopper became a well-recognized figure toward the end of her life. She was the recipient of more than 40 honorary degrees, and many scholarships, professorships, awards, and conferences are named in her honor. In 1972 she received Yale’s Wilbur Lucius Cross Medal. In 1991 President George Bush awarded Hopper the National Medal of Technology, the nation’s highest technology award; she was the first woman to be so honored as an individual. In 1996 the Navy commissioned the U.S.S. Hopper, a guided missile destroyer. Kurt Beyer, author of “Grace Hopper and the Invention of the Information Age,” suggests that Hopper achieved so much attention and even “celebrity” late in life because a Republican Congressman from Illinois saw an interview with Hopper on “60 Minutes” in 1983. After seeing the interview he successfully introduced a bill to have Hopper promoted to the rank of commodore.

At the age of 79, Hopper retired as a rear admiral. She was the oldest serving officer in the U.S. Armed Forces. That same year she went to work as a senior consultant in public relations at the Digital Equipment Corporation, where she worked up until a year before her death in 1992. Hopper was buried with full military honors in Arlington National Cemetery.

In 2016 Hopper posthumously received the Presidential Medal of Freedom, the nation’s highest civilian honor, in recognition of her remarkable contributions to the field of computer science.

Visionary communicator and educator

Hopper was not only a brilliant mathematician and computer scientist; she was also a gifted teacher and communicator. Although she left the comfort of her faculty position at Vassar to join the Navy, teaching remained part of her life. In 1959 Hopper was a visiting and then adjunct lecturer at the Moore School of Electrical Engineering at the University of Pennsylvania. From 1971 to 1978 she served as a professorial lecturer in management sciences at George Washington University. Outside of academia, she organized myriad workshops and conferences to promote understanding of programming and expand the community of computer programmers. Throughout her time at Eckert-Mauchly and its successor companies she also continued to teach a seminar. In accepting the National Medal of Technology, Hopper said, “If you ask me what accomplishment I’m most proud of, the answer would be all the young people I’ve trained over the years; that’s more important than writing the first compiler.”5

Hopper’s talents as a teacher also helped her communicate with a wide variety of audiences — technical experts and engineers, business leaders and data processors, young people, and the general public. She helped persuade business clients of the value of adopting new technologies, and Beyer describes her as a “spokesperson for the evolving computer industry” in the 1950s.6 Hopper played a similar role for the Navy. From 1977 to 1986 she was “the Navy’s foremost propagandist for its computer program as …  [its] representative to learned societies, industry associations, and technical symposia.”7 In the last years of her life she did similar work in public relations for the Digital Equipment Corporation.

Hopper was also a clear writer. Under orders from Howard Aiken, she wrote the world’s first computer programming manual. Throughout her career she placed great value on documentation and being able to explain complex situations and problems to different audiences. “I’ve come to feel that there is no use doing anything unless you can communicate,” she said in a 1980 interview.8

During the Cold War, military and business investment in computer technology continued to grow. Nevertheless, many people remained skeptical of what computers could do or how they could transform new areas and applications. Hopper fervently believed that advances in computer science would continue to accelerate; she embraced and looked forward to the future. She often said she wanted to live until January 1, 2000, in order to see the unexpected advances computers had made by then — and laugh at the unbelievers. “I think we consistently continually [sic] underestimate what we can do with computers if we really try,” she said in 1980.9 This confidence that computers would become increasingly ubiquitous was a driving force behind her efforts to make them more user-friendly.


There are extensive archival collections about Hopper’s life. In addition to the Grace Murray Hopper Collection at the Smithsonian and relevant collections at other universities and research institutes, there are also thousands of pages of oral histories that were collected from Hopper and her colleagues over a 50-year period.

Despite these rich sources, there are no comprehensive biographies of Hopper. Kurt W. Beyer, “Grace Hopper and the Invention of the Information Age” (Cambridge: MIT Press, 2009),[i] concentrates on the period from 1945 to 1960, ending his substantive discussion of her life with the creation of COBOL.  Another helpful source is Kathleen Williams’ “Improbable Warriors: Mathematicians Grace Hopper and Mina Rees in World War II,” in B. Booss-Bavnbek  and J. Høyrup, eds., “Mathematics and War,” 108-125 (Basel: Birkhäuser, 2003).

Very little has been written about Hopper’s personal life. Hopper divorced her husband, an English teacher, in 1945. She never remarried or had children. Kurt Beyer discusses her struggles with alcoholism, depression, and suicidal thoughts in the 1940s, but his book does not detail how or if she recovered.

1. “Oral History of Captain Grace Hopper,” interview conducted December 1980 by Angeline Pantages, Naval Data Automation Command, Maryland, Computer History Museum, 1980, 11. Hereafter “Hopper Oral History.”

2. Beyer, “Grace Hopper,” 304, 310.

3. Kathleen Williams, “Improbable Warriors: Mathematicians Grace Hopper and Mina Rees in World War II,” in B. Booss-Bavnbek  and J. Høyrup, eds., “Mathematics and War” (Basel: Birkhäuser, 2003), 117.

4. Poor health prevented Hopper from receiving the award in person, but she prepared these remarks, which were delivered on her behalf. See Carmen Lois Mitchell, “The Contribution of Grace Murray Hopper to Computer Science and Computer Education” (Ph.D. diss., University of North Texas, 1994), 77.

5. Beyer, “Grace Hopper,” 11.

6. Williams, “Improbable Warriors,” 118.

7. “Hopper Oral History,” 26.

8. “Hopper Oral History,” 48.

9. For factual errors in Beyer’s book, see Judy Green and Jeanne LaDuke, “To the editor,” Isis 102, no. 1 (March 2011): 136-137. For example, Beyer erroneously states that Hopper was the first woman to receive a Ph.D. in mathematics from Yale.

Correction: An earlier version of this story incorrectly stated that Hopper had received a Ph.D. in “mathematics and mathematical physics.” Her doctorate was only in the former.

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