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 Circus
New York City Mayor Michael Bloomberg proclaimed November 1, 2002, as "Big Apple Circus Day". The circus celebrated its 25th anniversary with a documentary film about the creation and production of that year's show.