Grace Hopper

Verified Timeline

Lore & Background

Grace Hopper was born in New York City, the eldest of three children. Her great-grandfather, Alexander Wilson Russell, was an admiral in the US Navy who fought in the Battle of Mobile Bay during the Civil War. As a child, she dismantled seven alarm clocks to figure out how they worked. Later in life, she kept a clock that ran backward, explaining, "Humans are allergic to change. They love to say, 'We've always done it this way.' I try to fight that." She attended the Hartridge School in Plainfield, New Jersey, and was initially rejected for early admission to Vassar College at age 16 due to low Latin test scores, but was admitted the next year. She graduated Phi Beta Kappa from Vassar in 1928 with a bachelor's degree in mathematics and physics, earned her master's degree at Yale in 1930, and her Ph.D. in mathematics from Yale in 1934 under Øystein Ore. She married New York University professor Vincent Foster Hopper in 1930; they divorced in 1945, and she retained his surname. She began teaching mathematics at Vassar in 1931 and was promoted to associate professor in 1941. During World War II, she was initially turned down for Navy service because she was too old (34), her weight-to-height ratio was too low, and her job as a mathematician was considered valuable to the war effort. In 1943, she obtained a leave of absence from Vassar and was sworn into the United States Navy Reserve as one of many women in the WAVES. She needed an exemption to be commissioned because she was 15 pounds below the Navy minimum weight of 120 pounds. She trained at the Naval Reserve Midshipmen's School at Smith College, graduated first in her class in 1944, and was assigned to the Bureau of Ships Computation Project at Harvard University as a lieutenant, junior grade, serving on the Mark I computer programming staff headed by Howard H. Aiken. Hopper and Aiken co-authored three papers on the Mark I. After the war, her request to transfer to the regular Navy was denied because she was two years older than the cutoff age of 38. She continued in the Navy Reserve and remained at the Harvard Computation Lab until 1949, turning down a full professorship at Vassar. In 1949, she joined the Eckert–Mauchly Computer Corporation as a senior mathematician and worked on the UNIVAC I. When she recommended a new programming language using entirely English words, she "was told very quickly that [she] couldn't do this because computers didn't understand English." She persisted, saying, "It's much easier for most people to write an English statement than it is to use symbols." By 1952, she had an operational link-loader (then called a compiler) for the A-0 System. She later said, "Nobody believed that" and "I had a running compiler and nobody would touch it. They told me computers could only do arithmetic." In 1954, she was named the company's first director of automatic programming, and her department released MATH-MATIC and FLOW-MATIC. In spring 1959, she served as a technical consultant to the CODASYL consortium that defined COBOL, which extended her FLOW-MATIC language. From 1967 to 1977, she served as director of the Navy Programming Languages Group and was promoted to captain in 1973, developing validation software for COBOL. In the 1970s, she advocated for the Defense Department to replace large, centralized systems with networks of small, distributed computers.

Reader's Guide

Grace Hopper's significance lies in her foundational contributions to computer programming and software development. She was the first to devise the theory of machine-independent programming languages, which led to the creation of FLOW-MATIC and COBOL, an early high-level language still in use today. Her work on the first compiler (a program linker) for the A-0 System demonstrated that computers could translate English-like statements into machine code, making programming more accessible. Hopper also wrote the first computer manual, 'A Manual of Operation for the Automatic Sequence Controlled Calculator,' and was one of the first programmers on the Harvard Mark I. Her legacy is recognized through numerous honors: the U.S. Navy Arleigh Burke-class guided-missile destroyer USS Hopper was named for her, as was the Cray XE6 'Hopper' supercomputer at NERSC, the 'Grace' supercomputing cluster at Texas A&M University, and the Nvidia GPU architecture 'Hopper.' During her lifetime, she was awarded 40 honorary degrees from universities across the world. A college at Yale University was renamed in her honor. In 1991, she received the National Medal of Technology. On November 22, 2016, she was posthumously awarded the Presidential Medal of Freedom by President Barack Obama. In 2024, the IEEE dedicated a plaque at the University of Pennsylvania in honor of her invention of the A-0 compiler, which functioned as a linker/loader, during her time as a lecturer in the School of Engineering.

Did You Know?

• Grace Hopper dismantled seven alarm clocks at age seven to figure out how they worked, after which she was limited to only one clock.
• She kept a clock that ran backward on her wall, saying, "Humans are allergic to change. They love to say, 'We've always done it this way.' I try to fight that."
• She needed an exemption to be commissioned in the Navy because she was 15 pounds below the minimum weight of 120 pounds.
• By 1952, she had an operational link-loader (then called a compiler) for the A-0 System, but "nobody would touch it" because they thought computers could only do arithmetic.
• She was posthumously awarded the Presidential Medal of Freedom by President Barack Obama on November 22, 2016.

Common Misconceptions (Editorial)

Some people mistakenly believe Grace Hopper “invented” the first computer or the first programming language. In fact, she was one of the first programmers on the Harvard Mark I and pioneered machine-independent programming languages, but the Mark I and early computing existed before her work. Another common misconception is that the term “computer bug” originated from a moth she personally removed from the Mark II in 1947; however, the provided facts do not mention this story, so it cannot be verified here. A third error is that Hopper was a U.S. Navy admiral during her active service—she was actually commissioned as a lieutenant (junior grade) during World War II, served in the Navy Reserve, and was promoted to captain in 1973; she was posthumously awarded the rank of rear admiral in 2016, after her death in 1992.

Why It Matters (Editorial)

Grace Hopper matters because she refused to accept that computers could only speak in symbols, arguing instead that they should understand English—a vision that directly enabled the development of COBOL and made programming accessible to countless non-specialists. Her persistence in building the first compiler despite being told “nobody would touch it” reminds us that transformative technology often requires stubborn optimism against prevailing wisdom, and her military career proves that pathbreaking contributions can come from those who defy age, gender, and institutional barriers.

Notable Quotes (Wikiquote)

"From then on, when anything went wrong with a computer, we said it had bugs in it." — Grace Hopper "I handed my passport to the immigration officer, and he looked at it and looked at me and said, "What are you?" — Grace Hopper "In total desperation, I called over to the engineering building, and I said, "Please cut off a nanosecond and send it over to me." — Grace Hopper "At the end of about a week, I called back and said, "I need something to compare this to. Could I please have a microsecond?" — Grace Hopper