US Postage Due stamp, overprinted for <a href="https://en.wikipedia.org/wiki/Postage_stamps_and_postal_history_of_the_Canal_Zone" class="extiw" title="w:Postage stamps and postal history of the Canal Zone">Canal Zone</a>
US Government -- US Post Office
US Government; Bureau of Engraving and Printing -- image obtained from eBay, May 20, 2018