Among the great cities in the world—Paris, Chicago, or New Orleans, for example—none is better known by its nickname than New York City, "The Big Apple." Paris may be "The City of Lights," Chicago "The Windy City," and New Orleans "The Big Easy," but just mention "The Big Apple" and America's metropolis immediately comes to mind. New York is the nation's financial center, an entertainment, theater, and news capital, and the heart of the fashion and publishing industries. "The Big Apple," meaning the biggest, best, and brightest, seems to fit quite nicely.

A number of theories exist regarding the origin of New York's nickname. Some say it began as a term used in Harlem in the 1930s, meaning the biggest and best. Others have traced it to a dance craze called The Big Apple. The Museum of the City of...