Engineering in the U.S. has long been a male-dominated profession. Fifty years ago, it looked like that might change.

In 1970, the percentage of women majoring in engineering was less than 1%. In 1979, that number was 9%. Many hoped women would continue to enter the field at the same rate. But thafs not what happened. Today, only 21% of engineering majors are women, a number largely unchanged since 2000.

I am a historian who, along with my colleagues, surveyed 251 women engineers who graduated from college in the 1970s. These pioneers reflected on the challenges they faced- and had advice for women entering the field today.

One survey taker explained, <4The greatest challenge for me was continuing to believe in myself when all the messages I was getting were that I would never be taken seriously or promoted or given raises at the same rate as men, who were clearly less qualified and not as smart as I was.”

A chemical engineer who worked in manufacturing agreed, 4<You have to prove yourself just because you are female. And you have to work twice as hard!"

A civil engineer said, 4<We are 'women engineers/ People don't refer to a man as a 4man engineer?- he's an engineer. We are constantly reminded that we don't truly belong." Another civil engineer stated, "On many levels, you're never quite one of the groups."

Women also talked about family caregiving responsibilities. A retired vice president from a major chemical company stated, "Young women engineers are on an equal footing until they have children, then they struggle to balance work and family- and compete with men who don't have the same household responsibilities."

But over the years things have changed a lot. Young women engineers are more accepted mostly because there are just more of them.

Many women engineers hailed the benefits of their chosen career. A program manager in manufacturing stated that engineering is the best degree. A mechanical engineer said, "It will give you the flexibility to do almost anything. It is also satisfying to see the effects of what you have done."