I didn't believe it when I found it. My initial source is spoofable, though the cross-links would have taken a little more work and they try hard to prevent such things. Withal:
It appears the last Letter of Marque & Reprisal issued by the Federal government of the U. S. of A. was to the airship Resolute, in 1941; the blimp operated as a submarine-spotter out of Los Angeles in 1941 and '42. And they did have a rifle aboard, so we're talkin' armed privateer. (When you buy tires from Goodyear, you're doing business with the only surviving U. S. company to have operated a privateer vessel. I don't know if the Brits or other parts of the former British Empire have any. Did the French go in for privateering much?)
Airship privateer. The career I dreamt of* and it actually existed. At least for a few months.
Update: Commenter Justthisguy points to The Graf Zeppelin March and reports himself earwormed. What the heck -- earworms for everybody!
* Some of the time. You know, when I wasn't exploring outer space, bein' Pat Savage or pounding brass in the Merchant Marine.
4 months ago