[lonestar]

Maybe you’re too young to remember, but at one time black males were referred as bucks.

I thought of Harry Truman...and trust me, I'm old enough and remember. LOL!

[Poincare]

from trumanlibrary.org:

The saying “the buck stops here” derives from the slang expression “pass the buck” which means passing the responsibility on to someone else. The latter expression is said to have originated with the game of poker, in which a marker or counter, frequently in frontier days a knife with a buckhorn handle, was used to indicate the person whose turn it was to deal. If the player did not wish to deal he could pass the responsibility by passing the “buck,” as the counter came to be called, to the next player.*