Well, that isn't the date he threw it...That's the date they coined it.
7 seconds sound clip from The Danny Kaye Radio Show - "A Baby From Washington" (3.02.1945).
You can hear this line at 00:06:24 in the radio play.
Quote context
[...]
- Say, Danny, did you have a good time in Washington?
- Oh, just wonderful, just wonderful.
- And by the way, I brought back a present for you.
- I've got it right here in my pocket... here you are...
- The original silver dollar that George Washington threw across the Potomac.
- Hey, wait a minute...Look at the date on this buck. 1912.
- Well, that isn't the date he threw it...That's the date they coined it.
- Oh, I see. Why didn't I think of that? Gee, ain't I a dope?
- You have one dollar. Would you care to try for two?
- I don't know, but it should have been Lucresia Quivertonsil or Natalie No-throat or something.
[...]