The President, whoever he is, has to decide.
He can't pass the buck to anybody.
— Harry Truman
Harry Truman kept a foot-long sign on his desk in the White House that said, "The Buck Stops Here."
The saying derives from poker.
In frontier days, a knife with a buckhorn handle was used to indicate which player had the turn at dealing. If that player didn't want the responsibility, he would "pass the buck."
Most people mistake the "buck" in the expression to mean "dollar."
That meaning also derives from frontier days, not from poker, but from trading.
Deer hunting was common at the time, and buckskins could be used as legal tender. Traders valued a "buck" at one dollar.
They valued a doe at half a dollar.
Females have always been undervalued.
HAT TIP: Word-nerd Ann Ramsey inspired this post.