Harvard Business School's Great American Leaders database shares the names and stories of of individuals whose business acumen has shaped how people have lived, worked and interacted during the 20th century. The database stemmed from Harvard's Leadership Initiative, which strives to put into context the development and performance of leaders past in an effort to better prepare today's and tomorrow's leaders.

Sorted in a number of different ways, from gender to industry, some familiar faces in the database include Oprah Winfrey and Henry Ford. The online version of the database -- though robust in and of itself -- includes only a sample of the profiles the school has accumulated over a two-year research period. You must fill out a form to receive a full version.