This USPS $1 Airlift stamp issued in 1968 was used for mailing parcels to or from a military post office outside of the 48 contiguous United States. It guaranteed airmail delivery on a space available basis. This stamp was used most often to mail packages to US servicemen in Vietnam during the war years, when ordinary post was transported by ship. This stamp is mint, previously hinged, original gum. Scott Catalog > 1960s #1341.