This item was issued just a few weeks after the Sept. 1, 1939 Invasion of Poland by Nazi Germany, the Soviet Union and a Slovak contingent that marked the start of World War II. The date on the button is “Oct. 14th.” Button is attached through a slot to a die-cut celluloid in the shape of the Trylon so the button itself becomes the adjoining symbolic circular Perisphere. Base of the die-cut celluloid reads “American Polish Participation/New York World’s Fair, 1939.” The button is 11/16” and the die-cut cello is 1-9/16” tall. Rare, especially with the die-cut intact. Hake book Collectible Pin-Back Buttons photo example Expositions #333. Comes with Hake’s COA. Historic and Exc. displaying Mint. See next related item.