

When I was in law school I did a deep dive on the formation of Illinois and ended up going down a big rabbit hole of the dialects of Southern Illinois. The reason different parts of southern Illinois have accents that sound so different is because a lot of people settled there from Alabama, Georgia, Mississippi, and South Carolina, and even thought towns were closish to each other the accents were very different because of the group of southern settlers. Super interesting. Where I’m from in Southern Illinois people have a very unique and unmistakable accent.
Europeans have been settling in North America for 500 years. The United States being a young country has nothing to do with the evolution of accents and dialects. When the US was formed the Spanish had been in the Americas for 200 years, the French and English not much less, in addition to enslaved Africans who brought their own native languages to the continent and then were forced to learn English, Spanish, French, or Portuguese. That alone is more than enough time and groups of people for dialects and accents to develop.