A 30-year IBM veteran, she added marketing and strategy oversight to her role last year. The move positioned her as one of the company's top two candidates to replace current CEO Sam Palmisano, and it worked. Rometty will be Big Blue's next CEO, replacing Palmisano in January.
Boardroom battles and power plays shaped this year's U.S. list, which boasts eight new faces and -- surprise! -- a new No. 1.
|Technology and the fight against terrorism|
|Why blacks believe in the American Dream more than whites|
|'Captain America: Civil War' trailer debuts on 'Jimmy Kimmel Live'|
|Working while brown: What discrimination looks like now|
|The black-white economic divide in 5 charts|