Image #1
WORLDWIDE AIR POST STAMPS AND POSTAL HISTORY
United States
Lot #
14 | 
| Scott # C2
| 1918 (July 15), two First Flight covers Washington, DC - Philadelphia and New York - Washington, DC, the last one is reduced at left, each one franked by 16c green (new air mail rate started exactly on July 15), both mounted on page with detailed explanation, F/VF, Est. $700-$800 . |