Grace Hopper

Grace Hopper spent 27 years trying to convince skeptical colleagues that computers could be programmed in ordinary language rather than machine code — that a compiler could translate human-readable instructions into the binary commands a machine understood. She was right, and her persistence produced COBOL, the Common Business-Oriented Language that became the most widely used programming language in the world and still runs critical infrastructure today. She did this while navigating a Navy bureaucracy that retired her three times and recalled her twice, eventually promoting her to rear admiral at 79 — the oldest active-duty officer in the U.S. armed forces.

Hopper's path into computing began at Harvard in 1944, where she joined the team programming the Mark I electromechanical computer for the Navy Bureau of Ordnance. She worked with Howard Aiken and became one of the first programmers of a large-scale digital computer in the United States. When a moth was found causing a relay malfunction in the Mark II in 1947, it was taped into the logbook with the notation "first actual case of bug being found" — a story that Hopper told so often that she became permanently associated with the term debugging, though the word predated her use of it.

Hopper's deeper contribution was philosophical as much as technical. She argued consistently that programming languages should be accessible to anyone who could think logically, not just to mathematicians or engineers — a democratizing instinct that prefigured the personal computer era. She died in 1992 and was buried with full naval honors at Arlington National Cemetery. In 2016 she was posthumously awarded the Presidential Medal of Freedom. The Navy destroyer USS Hopper was named in her honor.