Big Apple
"The Big Apple" was popularized as a name for New York City by John J. Fitz Gerald in a number of horse-racing articles for the "New York Morning Telegraph" in the 1920s. The earliest of these was a casual reference on 3rd May, 1921:
Big Apple
In the early 1970s, however, the New York Convention and Visitors Bureau (now NYC & Company, New York City's official marketing and tourism organization) began to promote the city's "Big Apple" nickname under the leadership of its president, Charles Gillett. It has remained popular since then.