I think Carolina crops up a lot in song because of its amenable Italianate scansion (short, short, long, short syllables), plus it’s versatile rhyming possibilities:

Nothing could be finer than to be in Carolina in the morning
In my mind I’m gone to Carolina
When I was young and in my prime, I left my home in Caroline
Heading down south to the land of the pines, thumbing way to North Caroline
In South Carolina there are many tall pines.....

In short, a songsmith’s dream - can’t really claim that for Omaha, Idaho or Michigan, though a few million residents there might disagree.