Programming began as a female-friendly career: The dawn of computers coincided with World War II, requiring workers who wouldn't be drafted. Women in tech ascended--until the arrival of the personal computer. Now female founder-CEOs of tech companies, like BlackLine's Therese Tucker, are outliers.

1941-45

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The first digital computers are built for wartime purposes, including Eniac (pictured), the first fully electronic American computer, which in 1946 is originally programmed by six women recruited by the Army. Others include Great Britain's Colossus machines at Bletchley Park--which are operated by women in the British Navy, also known as Wrens.

1942

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Movie star Hedy Lamarr, a design-obsessed inventor in her spare time, patents a tech­nology that is later used to make U.S. missiles undetectable during the Cold War--and for the spread-spectrum communication technology that makes modern Wi-Fi and cell phones work.

1945

After World War II, as the commercial demand for computers and their programmers ramps up, employment opportunities for women increase. "There was no preexisting male work force to push them out," Janet Abbate writes in Recoding Gender: Women's Changing Participation in Computing. "Most of the sciences were closed to them," Abbate tells Inc., "but computing seemed wide open."

1949

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The creators of the Eniac, who had started the civilian computing company that developed the Univac machine, hire Grace Hopper (pictured left) as senior mathematician. She starts developing the first computer languages, including the Cobol programming language.

1956

Companies increasingly "employ only women" or "a high percentage of women" in their computing groups, according to the U.S. Department of Labor. This is the result of corporate America's needing people to write the code and move the cards in big punch-card-operated machines, so it hires women with and without college degrees who can pick up the job quickly.

1967

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"This is the age of the Computer Girls," declares Cosmopolitan magazine. A year later, IBM gears this recruiting ad toward women.

1969

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Neil Armstrong walks on the moon, a mission made possible by the calculations of women mathematicians and systems engineers such as Katherine Johnson (left) and Margaret Hamilton, who developed the Apollo spacecraft's onboard flight program, inventing the modern concept of "software" in the process.

1971-2015

The advent of the personal computer, paired with the emergence of "geek" culture in the late 1970s, starts to shift perceptions, propagating prejudices that females aren't good at math and science. Once considered unglamorous clerical work, computer programming soon becomes coveted, highly skilled labor.

As tech becomes a major industry and the number of people studying computer science increases, the gulf between men and women receiving degrees widens.