On 2 July 1944, a freshly minted lieutenant (junior grade) entered the basement office in Cruft Laboratory at Harvard University, relieved that she finally had reached her destination. Commander Howard Aiken looked up at the slender young female officer.
“Where the hell have you been?” he demanded.
The lieutenant tried to explain how she had started out at Navy headquarters in Boston, then continued her search at various university buildings before arriving, hours late, at the laboratory. The commander brushed off her explanation.
“I mean for the last two months!” he exclaimed.
The lady’s reputation as an experienced and exceptionally bright mathematician had preceded her, and Aiken badly needed her skills. He gestured toward a glass-encased 51 -foot-long apparatus, which was clacking like a roomful of people knitting. It was the Mark I computer at labor, its 3,300 electrical relays opening and closing.
“That’s a computing engine,” he said. “I would be delighted to have the coefficients for the interpolation of the arc tangent by next Thursday.”
This was young Lieutenant Grace Murray Hopper’s introduction to the world of computers and the beginning of a “tour of duty” unparalleled in its impact on automatic data processing in the Navy. Throughout her long and immensely productive career, demand for her expertise—both in the sea service and the business world—never waned.
Grace Murray, the daughter of an insurance broker and oldest of three children, was born in New York City in 1906. One ancestor was a Minute Man, and her great-grandfather, Alexander Wilson Russell, was a Navy rear admiral. But Hopper’s principal inspiration, according to her biographer, Charlene W. Billings (author of Grace Hopper, Navy Admiral and Computer Pioneer), was her father.1 When hardening of the arteries left him a double amputee, he told his children that, if he could walk with two wooden legs and two canes, they could do anything. The young Grace was imbued with this unquenchable let’s-get-on-with-it spirit.
A Phi Beta Kappa student, Grace earned a B.A. in mathematics and physics from Vassar College in 1928 and an M.A. and a Ph.D. in math at Yale in 1930 and 1934, respectively. She married Vincent Foster Hopper in 1930 (a childless union that ended in divorce in 1946) and taught mathematics at Vassar until 1943.
After the U.S. entry into World War II, Hopper desperately wanted to join the Navy and be part of the war effort. Displaying characteristic drive, she negotiated a number of administrative hurdles, including a weight waiver—her 105 pounds was 16 pounds shy of the official minimum—and enlisted as a reservist in December 1943. Her sharp intellect and military demeanor proved to be a successful combination, and she graduated first in her class at the U.S. Naval Reserve Midshipmen’s School for women at Northampton, Massachusetts. Hopper was attending the school on D-Day, 6 June 1944, when the Allies began the invasion of Europe, and she attended a special service at the chapel. From that day on, Grace Hopper wore her uniform on 6 June in commemoration of that event, and on 7 December, in remembrance of Pearl Harbor.
After her commissioning as a lieutenant (junior grade) in June 1944, Hopper laid flowers on her great-grandfather’s grave. It’s “all right for females to be Navy officers,” she assured him.
Hopper’s first assignment was to the Bureau of Ordnance Computation Project at Harvard University, where Commander Aiken was deeply immersed in producing ballistic tables and other data for the Navy by means of the Automatic Sequence Controlled Calculator, or Mark I.
For generations, scientists had sought ways to speed up mathematical calculations. Nineteenth century Englishman Charles Babbage, a pioneer in the field, developed an “analytical engine” controlled by punched cards. The plans for Babbage’s engine were developed by Ada Byron Lovelace—daughter of poet Lord Byron and the world’s first computer programmer.2
Grace Hopper believed Commander Aiken to be the first true successor to Babbage. Like Hopper, Aiken was a visionary, who contended that computers would one day fit into a shoe box—a contention belied by the mammoth dimensions of the Mark I.
A gift to Harvard from IBM, the sprawling, five-ton Mark I featured a four-horsepower motor, which drove a rotary shaft running the length of the machine. Five hundred miles of wire weaved through the apparatus and its 800,000 parts. Its vast array of switches (or relays) opened and closed as it took input signals from a continuous stream of punched IBM cards and worked out solutions. IBM electric typewriters produced output—the results of the calculations. Grace Hopper once remarked, “The Mark I was the prettiest gadget I ever saw.”
“When they [fellow officers Bob Campbell and Dick Bloch] suspected a relay had failed, they would turn out the lights and go behind the front panel of the computer,” Billings explained. Grace would use a purse-sized mirror to locate telltale sparks from the relay that had faltered.
One day a computation error prompted technicians to stop the machine. When they traced the difficulty to the malfunctioning relay, they found a two-inch moth wedged between the relay contacts. They removed the moth, which solved the problem and introduced the term “debugging” into the computer lexicon. The moth was affixed to an appropriate page in the daily log book and is now on display at the Smithsonian Institution.
In the frenetic days of the war, the Mark I labored around the clock. In addition to ballistic tables, the Mark I calculated the area covered by a towed minesweeping device and simulated shock waves that would result from an atomic bomb explosion. Hopper “coded” the Mark I—issuing it the proper instructions so it could generate solutions.3
By the summer of 1945 the Mark II was being built. Five times faster than Mark I, it was still huge—occupying 4,000 square feet. Hopper sensed the vast potential of computer technology. Thankfully, the Navy agreed. “The Navy recognized that what we were doing was extremely important,” she noted. “We felt then that we would be able to solve in days, problems that ordinarily might take years.”
After the war, Grace had to leave the Navy for the Naval Reserve; she was 40 years old, and 38 was the limit. This was the first of many times she would be considered too old. She elected to remain at the Computation Laboratory, however, reinforcing and expanding her skills while teaching others how to work computers. The Mark III, with its vacuum tubes and magnetic tape, was on its way, along with the capability of producing solutions 50 times faster than the Mark I.
Many people still believed there would be no need for large numbers of computers, but Hopper was among the few who saw their limitless future. In 1949, she left academia to work with Eckert- Mauchly Computer Corporation in Philadelphia as the senior mathematician.
Eckert-Mauchly had built the Electronic Numerical Integrator and Calculator (ENIAC)—the world’s first general- purpose electronic computer—at the University of Pennsylvania. It required so much power (200 kilowatts) that the lights of Philadelphia were said to dim when it was turned on. A decimal-oriented machine, the ENIAC used a far greater number of electronic vacuum tubes than its successor, the binary-coded EDVAC.
BINAC, Eckert-Mauchly’s follow-up to EDVAC, was nearly finished when Hopper joined the firm. Taking advantage of her teaching proficiency, the company sent her to California to train Northrop Aircraft personnel how to use BINAC for a classified project involving the Snark missile.
In 1951, UNIVAC I, an outgrowth of BINAC, became the first mass-produced computer designed for commercial purposes. It could make 3,000 additions or subtractions per second and was 1,000 times faster than the Mark 1. When the code for UNIVAC was written, Grace Hopper was right alongside.
“Grace Hopper knew the key to opening up the world of computers to broader nonscientific and business use was in the further development and refinement of programming languages,” noted Charlene Billings. “Languages were needed that could be understood and used by people who were not mathematicians or computer experts.”4 This was Grace Hopper’s greatest contribution to the advancement of computers: she knew they had to be user-friendly if they were to be adopted on a broad scale. One way to achieve this was to develop a plain English set of instructions so that the computer could write its own programs.
Hopper, who “viewed each of the letters of the alphabet as simply another kind of symbol, just like mathematical symbols,” helped produce Flowmatic, a “compiler” program that was the first to employ English words for computer instructions. She was going against the grain. A majority of scientists steadfastly believed that computers could understand only numerical codes.
In 1959, an industry-government committee was convened to develop a standard computer language. The result was Common Business Oriented Language (COBOL). The New York Times, on 26 August 1960, declared, “COBOL...substitutes simple English key words for present complicated numerical jargon understood only by electronic computer specialists to ‘instruct’ a computer in its functions.” Grace Hopper’s influence was evident.
The Defense Department adopted COBOL, and firms seeking DoD business understandably followed suit. Meanwhile, Dr. Grace Hopper was becoming known industry-wide as a master in standardizing computer languages.
On 31 December 1966, Commander Grace Hopper was placed on the Navy’s retired list. Fiercely loyal to the Navy, she said, “It was the saddest day of my life.” It was a short-lived separation. In August 1967, at the age of 61, Hopper was summoned to temporary active duty, to assist in standardizing COBOL for the Navy and to persuade doubters that computers were the wave of the future. She was assigned to the staff of the Chief of Naval Operations (0P-90) as Director, Navy Programming Languages Group, Office of Information Systems Planning and Development, at the Pentagon.
Her initial six-month tour was extended and she eventually received orders to remain on active duty indefinitely. After publishing Fundamentals of COBOL, Hopper found herself on the road promoting computers.
“Grace Hopper was the best public relations person the Navy ever had,” said Rear Admiral Peter Cullins, the first commander of the Navy Automation Command (NAVDAC), where Hopper transferred in 1977. “She went out and spread the word to professional groups, business organizations, high schools, colleges, and universities. She had a great ability to turn young people on to computers and to the Navy. I received hundreds of letters remarking how terrific her presentations were. One of her messages was ‘Don’t quit. Age doesn’t matter.’”
Captain Lee Maice, also of NAVDAC, concurred. “Grace Hopper was also the best recruiter of technically oriented people the Navy had.” Young listeners reasoned that if Grace Hopper, with her focus on youth and her unreserved enthusiasm about computers, was in the Navy, then that was the place to be.
Officially retired from Eckert-Mauchly in 1971, Hopper stayed on the road, giving speeches, teaching, and spreading the word about the time-saving, efficiency-enhancing value of computers.
Meanwhile, she was promoted to captain in 1973, to commodore in 1983 (in The White House with President Ronald Reagan), and to rear admiral in November 1985. Upon achieving flag rank. Hopper notified friends to monitor her great-grandfather Russell’s grave for, “He may rise from the dead.”
Along the way. Hopper received numerous honors and awards, including 37 doctorates. She was inducted into the Engineering and Science Hall of Fame, joining George Washington Carver, Henry Heimlich, Jonas Salk, and Thomas Edison. In 1987, the Grace Murray Hopper Service Center of the Navy Regional Data Automation Center in San Diego was completed, with one section devoted to a Hopper museum. In September 1991, President George Bush presented her with the National Medal of Technology.
In 1986, she appeared with Morley Safer on CBS’s “Sixty Minutes,” bringing her knowledge and instructional skills to a nationwide audience. Safer, inquiring about the phenomenal speed of modern computers, asked Hopper to describe a nanosecond—a billionth of a second. She obtained a length of wire to represent the maximum distance that electricity can travel in a billionth of a second.
“Now, of course, it wouldn’t really be through wire,” she explained. “It’d be out in space, the velocity of light. So, if you start with the velocity of light, and use your friendly computer, you’ll discover that a nanosecond is 11.8 inches long— the maximum limiting distance electricity can travel in a billionth of a second.” Next, using a 984-foot of coil of wire, she explained, “Here’s a microsecond. I sometimes think we ought to hang one over every programmer’s desk ... so they know what they’re throwing away when they throw away microseconds.”
Grace Hopper retired from the Navy in 1986, at age 80. She continued her speaking engagements, donating all honoraria to Navy Relief, and kept active as a senior consultant for Digital Equipment Corporation.
In a telephone interview in 1991, Rear Admiral Hopper was strong of voice— and viewpoint—despite having been laid up because of a fall. Asked about her role as “The Mother of Computerized Data Automation,” she was quick to credit her mentor. Commander Aiken, and the Navy, for having the foresight to support the development of computer technology.
She also stressed the importance of selling computers to young people. “[Young people] are the best asset this country has,” she said. “You’d be surprised how many of them have their own computers aboard ship today. At Sperry, I would award students free time on the computer,” she added. “‘Make the computer work for you. Let your mind soar!’ I told them.”
Grace Murray Hopper died at her home in Arlington, Virginia, on New Year’s Day 1992 at the age of 85. She was buried in Arlington National Cemetery with full honors.
“Grace used to conclude almost all her speeches with the same words,” remembered Admiral Cullins. “She would say, ‘I’ve received many honors, and I’m grateful for them. But I’ve already received the highest award I’ll ever receive—no matter how long I live, no matter how many different jobs I may have—and that has been the privilege and honor of serving very proudly in the United States Navy.’”
Grace Hopper was a teacher, a patriot, and a genius, but the sobriquet that fits best of all is “Amazing Grace.”
1. Charlene Billings, Grace Hopper, Navy Admiral and Computer Pioneer, (Hillside, N.J.: Enslow Publishers, Inc.), 1989, p. 15. Billings’s biography was a major source for this story.
2. Ada, a universal standard computer language, was named in her honor by Pentagon officials.
3. There was no such thing as a “programmer” then, although the term was being used in England. It took several years for “program” to replace “code” in the United States.
4. Billings, p. 68