Thomas Alva Edison: Transformed American industry and culture by inventing the phonograph and the motion picture camera and developing a long-lasting electric light bulb. Known as the Wizard of Menlo Park, Edison also founded General Electric. In this photo from 1877, Edison stands with the phonograph.
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Henry Ford: Brought automobiles to the masses through his Ford Motor Co. and pioneered the use of assembly-line manufacturing. In this 1927 photo, Ford drives his company's first vehicle, the Quadricycle.
Walt Disney: Revolutionized animation and inspired iconic characters, stories and Walt Disney Co. theme parks that have become a permanent fixture in popular culture. Disney posed with a Donald Duck character while reading from Alice in Wonderland during a 1951 movie premiere in London.
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Bill Gates: Brought cheap, usable software to the masses and helped shepherd in the age of the Internet – though some business pundits cast him as more innovator than visionary. The Microsoft co-founder, seen in this September 2002 photo, went on to become one of the world's richest people.
Steve Jobs: Co-founded Apple Computer, which radically changed the way people use computers through the use of the mouse and user-friendly operating systems. Developed the iPod, iPhone and iPad as well as the iTunes online music store. In this April 2010 photo, Jobs unveiled the new iPhone OS4 software in Cupertino, Calif.