This souvenir sheet was issued in honor of the American Philatelic Society's convention in Chicago in August 1933. Each sheet contains 25 stamps, without perforations or gum on the back. The marginal inscription reads: "PRINTED BY THE TREASURY DEPARTMENT, BUREAU OF ENGRAVING AND PRINTING--UNDER AUTHORITY OF JAMES A. FARLEY, POSTMASTER GENERAL, AT A CENTURY OF PROGRESS--IN COMPLIMENT TO THE AMERICAN PHILATELIC SOCIETY FOR ITS CONVENTION AND EXHIBITION--CHICAGO, ILLINOIS, AUGUST 1933."