ENIAC, the first general-purpose, programmable digital computer, developed at the University of Pennsylvania for the US army and completed in late 1945. The machine was revolutionary for its time, but would soon be obsolete in two ways: (1) it used decimal, rather than binary arithmetic; and (2), it was built on vacuum tubes. In 1947, the invention of the transistor, which replaced the costly and unreliable vacuum tubes, paved the way for the digital revolution.
The history of computing goes much further back, of course. The first programmable, mass-produced machine was the Jacquard loom, which was programmed by punch cards and occasioned the development of the Luddite movement, as skilled textile workers now became replaceable by machines. In those days, a computer was a person who performed calculations, generally rote work like calculating logarithmic tables. Interestingly, although mathematics has traditionally been an area largely closed off to women, many women did important work in the early history of computing.
The most famous name is Ada Lovelace, daughter of Lord Byron. She could by rights be called the first computer programmer, as she wrote programs for Charles Babbage’s analytical engine, which would have been the first general-purpose computer if it had ever been completed. Sadly for Babbage and for Lovelace, they were a hundred years ahead of their time. But countless others worked behind the scenes. Many women were hired as manual computers, partially because of their skill and partially because by the gender norms of their time, they could be paid less than men. One such group of women were “Pickering’s Harem,” women who processed astronomical data for Edward Charles Pickering, head of the Harvard Observatory from 1877-1919.
Six women were the primary programmers on ENIAC. In 1997, they finally received their due credit.