I know that the current border of Slovakia and Poland goes back to the border between Hungary and Galicia, and that many languages we like to think of having distinct boundaries are actually dialect continua. So, I'm wondering if there has historically been a difference on both sides of the Beskids, or if the boundaries have just arisen out of political necessity.

I'm mainly interested since my grandmother's family comes from the Beskids, near Kraków, and I have several ancestors from both sides of the Slovak-Polish (Hungarian-Galician) border.