First United States airmail issue
Well documentedSupported by multiple reputable specialist catalogues or publications.
Period
1918
Issuing entity
United StatesThe first United States stamps issued specifically to prepay airmail postage.
Historical context
Issued for the inaugural scheduled airmail service; one denomination is famous for an inverted centre error recorded separately.
Catalogue references
No catalogue numbers recorded. Numbers are only published once transcribed from a verified edition of a standard catalogue — they are never inferred.
Research required
- Catalogue numbers and printing quantities await transcription
- Plate number blocks and positions need a specialist reference