I think regionalisms are better approached systematically, as there are tons of scientific literature on this and even a Wikipedia article with an overview: https://en.wikipedia.org/wiki/American_English_regional_vocabulary (same for accents https://en.wikipedia.org/wiki/North_American_English_regional_phonology but that might require a fundamental study of English phonology)
I think regionalisms are better approached systematically, as there are tons of scientific literature on this and even a Wikipedia article with an overview: https://en.wikipedia.org/wiki/American_English_regional_vocabulary (same for accents https://en.wikipedia.org/wiki/North_American_English_regional_phonology but that might require a fundamental study of English phonology)