The Fifteen-cent Prexie
Canal Zone airmail usage
The rate for airmail letters to and from the Canal Zone and the continental United States was fifteen cents from December 1, 1937 to April 1, 1945.
It is generally easier to find mail directed to the Canal Zone than from it to the continental United States. This card was mailed from Washington, D.C. on May 20, 1941 and reached Corozal on May 22.