Grace Hopper

Grace Brewster Hopper was born Grace Murray in New York City on December 9, 1906, and died on January 1, 1992. She served as a rear admiral in the United States Navy and worked as a mathematician and computer scientist. A programming pioneer, Hopper originated the idea of machine-independent programming languages. She turned that concept into reality with the FLOW-MATIC language and COBOL, a high-level language that remains in active use. She also worked on the Harvard Mark I computer as one of its earliest programmers and authored the first computer manual, titled "A Manual of Operation for the Automatic Sequence Controlled Calculator."

Hopper earned a Ph.D. in mathematics from Yale University before joining the Navy and taught mathematics at Vassar College. During World War II, she left Vassar to enter the United States Navy Reserve. Her computing career began in 1944 on the Harvard Mark I team, which Howard H. Aiken led. In 1949, she moved to the Eckert–Mauchly Computer Corporation, where she helped build the UNIVAC I computer and managed the creation of one of the first COBOL compilers. She argued that programming should be easier by using English-based languages, and her compiler translated English terms into machine code. By 1952, she had completed a program linker, which she called a compiler, for the A-0 System. In 1954, Eckert–Mauchly put her in charge of automatic programming, and she oversaw the release of early compiled languages such as FLOW-MATIC. In 1959, she joined the CODASYL consortium, which created COBOL as a machine-independent language built from English words, and she spent the 1960s promoting it.

A U.S. Navy guided-missile destroyer, the Cray XE6 "Hopper" supercomputer at NERSC, the "Grace" supercomputing cluster at Texas A&M University, and the Nvidia GPU architecture "Hopper" all bear her name. She received 40 honorary degrees from universities worldwide, and a college at Yale University was renamed for her. In 1991, she was awarded the National Medal of Technology. On November 22, 2016, President Barack Obama posthumously gave her the Presidential Medal of Freedom. In 2024, the IEEE placed a plaque at the University of Pennsylvania honoring her invention of the A-0 compiler, which functioned as a linker and loader, during her time as a lecturer there.

Hopper was the eldest of three children, born to Walter Fletcher Murray and Mary Campbell Van Horne, who were of Scottish and Dutch descent and attended West End Collegiate Church. Her great-grandfather, Alexander Wilson Russell, was a Navy admiral who fought at the Battle of Mobile Bay in the Civil War. As a child, she was intensely curious—at age seven, she took apart seven alarm clocks to understand how one worked, after which her mother limited her to a single clock. Later, she kept a clock that ran backward, explaining that people resist change and say, "We've always done it this way," and she wanted to fight that attitude. She attended the Hartridge School in Plainfield, New Jersey. Initially rejected from Vassar College at age 16 due to low Latin scores, she was admitted the next year, graduated Phi Beta Kappa in 1928 with a bachelor's in mathematics and physics, and earned a master's from Yale in 1930.

In 1930, she married Vincent Foster Hopper, a New York University professor; they divorced in 1945, and she kept his surname. She earned her Ph.D. in mathematics from Yale in 1934, supervised by Øystein Ore, with a dissertation titled "New Types of Irreducibility Criteria." She began teaching mathematics at Vassar in 1931 and became an associate professor in 1941.

During World War II, Hopper tried to join the Navy but was turned down because she was 34—too old—and her weight-to-height ratio was too low; her job as a mathematician and professor was also deemed valuable to the war effort. In 1943, she took a leave from Vassar and joined the Navy Reserve as part of the WAVES. She needed an exemption to be commissioned because she was below the Navy's minimum weight. She trained at the Naval Reserve Midshipmen's School at Smith College in Northampton, Massachusetts, graduated first in her class in 1944, and was assigned as a lieutenant, junior grade, to the Bureau of Ships Computation Project at Harvard, working on the Mark I under Howard H. Aiken. She 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, so she stayed in the Reserve. She remained at the Harvard Computation Lab until 1949, turning down a full professorship at Vassar to continue as a research fellow.