Apart from a day in Gibraltar I've never visited any English-speaking country, so my knowledge of British, Irish, American and Canadian accents is based solely on television shows and movies. But then it depends on how true to their accent people are. You can probably rule out a lot of movies. But still, I can hear Mary Cooper from the Big Bang Theory is from Texas, and sometimes Sheldon as well. On the other hand I don't hear it so much in the people in Fast'n'Loud, they're just "American" to me. I can pick out some Canadian accents (I discovered "The Liquidator" is Canadian because of his accent). I just listened to a Newfoundland accent on youtube but to me it sounds different from Irish (at least different from Eddie Jordan or Michael Gambon).
To me American/Canadian accents differ less than England-English differs from Scotland-English. But maybe that's just me
Even in a small country like the Netherlands there are big differences. I don't know if anyone here is familiar with the show "The Incredible Dr. Pol"? He's Dutch, but lives in Michigan. His son Charles therefore doesn't speak Dutch, but he wanted to learn it when his uncle (Dr. Pol's brother) had planned to visit them in Michigan. At one point during that episode, uncle says something in Dutch, to which Charles (who has by then a basic understanding of the language) comments "yeah... I didn't catch that". Well, me neither... That's because the Pol family is from a different part of the country than I am, and I have a hard time understanding people from that region as well (I have an uncle who lives there, 90% of the time I have no idea what he's saying, and you can only ask one to repeat what he said so many times before they get annoyed, so I just mumble something that could be yes or no at hopefully appropriate moments).
To me American/Canadian accents differ less than England-English differs from Scotland-English. But maybe that's just me
Even in a small country like the Netherlands there are big differences. I don't know if anyone here is familiar with the show "The Incredible Dr. Pol"? He's Dutch, but lives in Michigan. His son Charles therefore doesn't speak Dutch, but he wanted to learn it when his uncle (Dr. Pol's brother) had planned to visit them in Michigan. At one point during that episode, uncle says something in Dutch, to which Charles (who has by then a basic understanding of the language) comments "yeah... I didn't catch that". Well, me neither... That's because the Pol family is from a different part of the country than I am, and I have a hard time understanding people from that region as well (I have an uncle who lives there, 90% of the time I have no idea what he's saying, and you can only ask one to repeat what he said so many times before they get annoyed, so I just mumble something that could be yes or no at hopefully appropriate moments).