Clemente was an exceptional baseball player whose career sheds light on larger issues of immigration, civil rights and cultural change.
Equipment failure, human error and bad luck led to the country's worst nuclear accident in 1979.
Originally settled as a mail stop, Las Vegas changed from an Old West vacation town, to a mafia haven, to the "Atomic City" and "Sin City."
With data compiled from tens of thousands of sex questionnaires, Alfred Kinsey changed America's views about sex with the Kinsey Reports.
The unusual life of David Vetter, who lived permanently inside a germ-free environment due to severe combined immunodeficiency.
In 1967, thousands of hippies flocked to San Francisco's Haight Ashbury district.
P.T. Barnum -- huckster, con man, promoter, entertainer and founder of "The Greatest Show on Earth".