When Ursula Burns found herself on the compound of the Xerox Corporation as a young engineering intern 29 years ago, she had already travelled a long way: far from the tenement building on the Lower East Side of Manhattan that was her home, and far from the embrace of her single mother, Olga.

But that was only the start of the journey. Burns, now 50, has been named as the next chief executive officer of the copier giant, becoming the first African-American woman to lead a company in the top 150 of the Fortune 500. It is also the first time that the top job at such a large company has passed from one woman to another. Stepping down from the post on 1 July after eight years is Anne Mulcahy.

It is a milestone for Burns and for Xerox but also for the country and its minority communities. Black Americans who continue to believe their chances for success are automatically smaller may be starting to notice changes all over the country, not least by looking at the new tenants in the White House.

Not that anyone who knows Burns seems surprised by the appointment. After rising through the ranks of the company, she has been serving as president of Xerox since 2007. "Ursula takes on the leadership role the old-fashioned way," Mulcahy told shareholders at an AGM on Thursday. "She has earned it. And, for that, she has my deep respect and confidence."

"Ursula is a very special talent," said Kevin Warren, the head of Xerox Canada who is also black.

"For her to enter the company as an intern, and as an engineer and a woman – period – and rise to the top level says a little bit about the culture of Xerox." The cultural significance of her rise was highlighted by John Engler, the president of the National Association of Manufacturers, who first met Burns five years ago. "She has been to business what Condi Rice is to politics," he said. More than ever, she will be a role model for young blacks in the US.

In some ways, Burns' story is typically American. Her childhood was one of material modesty, regardless of her skin colour. Olga had three daughters from two different men who played almost no part in the family's life. Ironing shirts and running a day-care centre in her home were the only forms of income, but she still managed to put her girls through a private Catholic school.

It was Burns' aptitude at mathematics that propelled her as a child, first across New York's East River to a polytechnic in Brooklyn that has since become a part of New York University, and eventually to a master's degree programme in the engineering school at Columbia University.

Once at Xerox, she met and then married Lloyd Bean, a scientist 20 years her senior and now retired.

For watchers of Xerox, an icon on the corporate landscape of the US that was close to bankruptcy when Mulcahy came to the top job in 2001, it was always a question of when, not if, Burns would take over.

Warren describes her as: "Very, very smart. Her ability to process information quickly, and recall, understand and simplify complex issues is absolutely amazing."