Big Apple
"Big Apple" is a nickname for New York City. It was first popularized in the 1920s by John J. Fitz Gerald, a sports writer for the "New York Morning Telegraph". Its popularity since the 1970s is due in part to a promotional campaign by the New York tourist authorities.
Barry Popik
Barry Popik (born 1961) is an American etymologist who is recognized as an expert on the origins of the terms "Big Apple", "Windy City", and "hot dog". He is a consulting editor of the "Oxford Encyclopedia of Food and Drink in America" and was described in "The Wall Street Journal" as "the restless genius of American etymology".