So when Washington Irving used the term, he was putting his finger on the peculiar blend of lunacy, wiliness and bravado that characterizes New York City.
The moniker became popular once again with the Batman & Batwoman comic books, which appeared more than a century later in 1939; the title character was said to live in Gotham City, clearly recognizable as New York.
The nickname "the Big Apple" has a much more recent derivation; it was coined around 1920 by jazz musicians from New Orleans. In New Orleans slang, to play in the big apple meant to play the big-time shows. By 1920 New York City was the principle city for jazz, and so over time it became known as the Big Apple.
Sports writer John J Fitz Gerald helped to popularize the term with his racing column of the 1920's, "Around the Big Apple". ("There's only one Big Apple. That's New York," he wrote in his column in 1924.) He'd heard the name from his stable hands, who had picked it up from the jazz circuit. The nickname became official in the 1970's, when the New York Convention and Visitor's Bureau started the Big Apple publicity campaign to attract tourists to the city.