Transcript for Mary Barra Is New CEO at General Motors
january. Also today a pioneering day for american business. For the first time one of the top auto makers in america put a woman in the driver's seat of the company as ceo. Abc's chief business reporter rebecca jarvis tells us about cars and what is changing in america. Reporter: In "mad men," the old boys of advertising courted the old boys of the auto industry. Whatever you fellas want. Reporter: Today it's what mary barra wants. I would like to introduce you to your new ceo. Reporter: Barry is the first woman ever to run one of detroit's big three. A homegrown talent who started at gm in 1980, inspecting pontiac grand prixs coming off the assembly line. Her father, a 39-year-old gm veteran was making car fenders and hoods. You stood outside the dealerships looking for the new vehicles. That's kind of how I was raised. Reporter: She's become a force at gm, overseeing global product innovation, with a focus on fuel efficiency and hybrids. Barra will be one of just 21 women running fortune 500 companies, joining hewlett packard's meg whitman, pepsico's indra nooyi and yahoo's marisa mayer. Firms with more women at the top earn 50% higher profits than those without. And a woman at gm could have other benefits. After all, it is women who make 80% of the car purchase decisions. Barra's original dream car? This red vintage chevy camaro. She wanted a firebird but settled for a chevy chevette. Today she drives a cadillac cts and on the weekends a corvette. I like cars that go fast. Reporter: Now after her slow and steady climb, it's full speed ahead. Rebecca jarvis, abc news, new york.
This transcript has been automatically generated and may not be 100% accurate.