- | forever | multi | Severo Ochoa |
- | forever | multi | Mark Twain |
- | forever | multi | Owney |
X | forever | multi | clipper ship | |||
X | forever | multi | auxiliary steamship | |||
X | forever | multi | Liberty ship | |||
X | forever | multi | container ship |
- | forever | multi | — | — | ||
- | forever | multi | — | — | ||
- | forever | multi | — | — | ||
- | forever | multi | — | — |
- | forever | multi | Navy Medal of Honor | |||
- | forever | multi | Army Medal of Honor |
- | forever | multi |
X | 6c | org | Curtiss Jenny | |||
X | 16c | grn | Curtiss Jenny | |||
X | 24c | carrose & bl | Curtiss Jenny | |||
- | 24c | carrose & bl | Curtiss Jenny, v. center inverted | 10,000 – 100,000 | 10,000 – 100,000 |
X | 8c | dkgrn | propeller & radiator | |||
X | 16c | dkgrn | emblem | |||
X | 24c | car | De Havilland biplane |
X | 10c | dkbl | mail planes on map of United States | |||
X | 15c | olbrn | mail planes on map of United States | |||
X | 20c | yelgrn | mail planes on map of United States (1927) | 1.00–10. | 1.00–10. |
X | 10c | dkbl | Spirit of St Louis on map of Atlantic |
X | 5c | car & bl | Beacon on Rocky Mountains |
X | 5c | vio | winged globe |
X | 65c | grn | zeppelin over Atlantic | |||
X | $1.30 | brn | zeppelin between continents | |||
X | $2.60 | bl | zeppelin & globe |
X | 50c | grn | baby zeppelin |
X | 25c | bl | China Clipper over Pacific |