It is probable (although not certain) that we have almost the exact date for the "Big Apple" utterance by the New Orleans Fair Grounds stable hands. John J. Fitz Gerald wrote that he had met Jake Byer at the Fair Grounds when this happened. I found this piece of the puzzle, from the New York Morning Telegraph, January 15, 1920, pg. 3, column 1:


J. J. Fitz Gerald has sold the 3-year-old colt Dunsandel to J. Byer and the aged plater Onwa to G. R. Allen at private terms. Allen will ship Onwa to Tia Juana to-night.