The word slave stems from the Slavs. Otto the Great captured and sold so many Slavic citizens that the word slave started to change meaning.
The original meaning did not get lost though.
You don't see many Hollywood productions about white slaves.
Otto the first did not trade cross-Atlantic. Neither did the Romans.
There are of course other reasons than that.
The white slaves that have been there for millennia in Europe did mingle in with the rest of the people. And over time traces of names were gone too. So it is not visible who stems from slavery and who not.
Slavery from the seventeenth century was, in the white part of the world, race based, very visible, and it was a cross-ocean thing. The whole world was part of it. From people selling people in Africa, to sailors and merchants bringing them across the ocean, to people buying them.
Mixing over time happened too, but visual traces are not gone. Who knows how that will be after a few more centuries.
Also, it is not that long ago, and lots and lots of nations were involved. Way bigger impact on historic memory.