US $1 Silver Certificate Federal Reserve note, 1935A series, Hawaiian overprint, star note.
Issued in 1942 in the run-up to WWII hostilities with Japan.

One of my favorite kinds of bills for the story they tell.

Wikipedia:
"A Hawaii overprint note is one of a series of banknotes (one silver certificate and three Federal Reserve Notes) issued during World War II as an emergency issue after the attack on Pearl Harbor. The intent of the overprints was to easily distinguish United States dollars captured by the Imperial Japanese Armed Forces in the event of an invasion of Hawaii and render the notes worthless."
https://en.wikipedia.org/wiki/Hawaii_overprint_note

In the end, about $35 million Hawaiian overprint $1 notes were issued. They were withdrawn (rendered not legal tender) in 1946, so most got returned in advance for legal bills, and the rest remaining stopped exchanging hands in the economy.

This one is further rare in that it is a "star" note (first digit in the serial is '*'). Those were printed in the event there were errors during printing, in which case the star note(s) of the same serial number (but with the initial '*' in lieu of the run letter) were inserted for circulation instead of the error notes keeping the serial number sequence continuous in spite of the pulled error notes. Of the $35M printed of $1 notes, only 196,000 star notes were used, in five distinct serial number blocks. So, not so common. This one happens to be from the largest of the blocks (72,000 notes)

I finally picked this one up last week. Paid top price for its condition, but having a good year and tired of waiting and getting outbid, lol.

There are also North African overprint notes with the same basic story but for the European conflict. Total number of those $1 notes issued was almost $27 million, and only 180,000 star notes were used, but they are much rarer for some reason. I'm guessing being in North Africa, fewer people hung on to the discontinued notes for collecting?