While I'm by no means a student of folk, it appears that early immigrants settled mostly along the east coast of the US, and tended to stick together and sing/play the music they brought with them.

As migration westward began, the migrating groups were sometimes more mixed so new songs relating to migration and settlement appeared.

The "folk music" collectors I've looked at - Warner and the Lomax tribe etc - tended to make much of "prison songs" and "chain gang chants."

The (un)Civil War, Prohibition (and the whole "Temperance" movement) and political campaigns produced a lot of songs, most which fortunately (opinion) have died without applause. While Europe seems to have called them "Music Halls" maybe "Vaudeville" was the US approximation(?). There have certainly been differences one can point to, but it's a puzzle, for me, which of them may have mattered.

I'm not sure that the "charts" will indicate any significant differences between the evolution of music here and there - and there - and there. Maybe it's just an idle curiosity.

John