“Talking turkey” comes from an encounter between a white settler and a Native American in 1848.
After they had bagged a turkey and a buzzard, the fast-talking white man suggested,
“You can have the buzzard and I will take the turkey, or I will take the turkey and you can have the buzzard”,
or in modern language, “Heads I win, tails you lose.”
The Native’s response, “Why don’t you talk turkey with me?” was passed on so often by those overhearing the argument that talking turkey became part of the language.