The US is one place where a regional or foreign accent is usually not considered unpleasant; they usually find it charming or at least interesting as long as they can understand what the speaker means.
In large Northern cities such as Chicago, Detroit, Cleveland, and Buffalo, certain vowel pronunciations are changing in ways that distance them from Southern vowels. For example, the augh sound of a word like caught is now pronounced more like the vowel of cot. Meanwhile, a word like lock sounds something like lack, while tack sounds a little like tech. At the same time, Southern vowels are changing in different ways. For example, red sounds something like raid, and fish sounds almost like feesh. So much for the presumed homogenization of Northern and Southern speech.(languagemagazine.com)
If someone in Chicago offered you some "sacks," you might think it was for carrying your groceries, not for keeping your feet warm. "Sacks" is how Chicagoans pronounce what we call "socks."
Coffee "cough ee" in upstate NY they say "cahh fee", in Brooklin "cuoof ee"
How about words like meet and meat used to be pronounced with distinct vowels (meet sounded like mate and meat something like met) though today these items have the same sound in most dialects of English.
English is a fascinating and flexible language , alwways changing; acquiring different words, pronunciation and grammar.
You don't need to speak "Queen's English" for people to know what you are talking about!