“Dr. Land,” as most people referred to him, left Harvard College before graduation to start inventing in a Cambridge garage. In 40 years, Land built up a company that did about $1.4 billion of business all over the world in 1979. He stuck to his guns, never diversified into other businesses, never sold out to another company, and never borrowed money on a long-term basis.

Pictured: In 1944, Land was asked by his 3-year-old daughter why she could not see the picture he had just taken of her. Her request led to the Polaroid Land Camera in 1948.