Florence Sabin in 1925. Also the first woman to become a full professor at the John Hopkins Medical School, Sabin’s research centered on embryology, the lymphatic system, and tuberculosis. Later in life, she became a crusading public health official in Colorado.

 

Smokey Bear. Found as a badly burned cub clinging to a charred tree in 1950 after a New Mexico forest fire, Smokey became the National Forest Service’s symbol and "spokesbear," reminding us, "Only you can prevent forest fires." He received so much fan mail that in 1964 the U.S. Postal Service gave him his own ZIP code, 20252.