Chicago Century of Progress Federal Building 3-cent 1933 issue U.S. stamp. The <a href="https://en.wikipedia.org/wiki/Century_of_Progress_International_Exposition" class="extiw" title="en:Century of Progress International Exposition">Century of Progress</a> was a World's Fair held in Chicago, as The Chicago World's Fair, from 1933 to 1934 to celebrate the city's centennial.
Bureau of Engraving and Printing
U.S. Postal Service; National Postal Museum: <a rel="nofollow" class="external text" href="http://arago.si.edu/category_2033018.html">Century of Progress Issue</a>