The North American accent is primarily an evolution from Scottish Irish accents. We hard roll our r’s—“carrrr”, “hearrrrt”—unlike the other colonial accents that don’t pronounce the r unless it hits another vowel.
It always made me wonder how they ever learn to spell words, as growing up in Canada we were always instructed to sound it out. Having said that, I can usually determine an American accent pretty quickly, but the U.S. rarely hear our accents as foreign. I also lived overseas and in Australia. I had another Canadian friend there that told me Aussies would regularly ask if he was Irish. I said “No way, they're mental… we do not sound Irish”.
To my disbelief when I first moved to Sydney, I got a job in a call centre for a telecom company, and to my surprise was asked quite a few times if I was Irish. Many take the hard r as Irish. Also to my great astonishment and surprise I had two or three ask if I was Canadian. “You're Canadian aren’t you?” always made me beam with pride. “Yes I am, I’m shocked you can clock my accent, most just think I’m a yank.” He said “No, mate it is subtle but there is a definite difference, once you are in fluid speech”. He said that we articulate more, he said that we do not use their “y’all” and those types of tells. He also remarked that cadence was a tell for him. The U.S. have regional tells in their speech. To unaware ears identical. To those that are fascinated by accents, it is easily picked out.
Anglophones in French Canada have a funny accent and use French expressions. For things like turning off the lights they will say “close the lights, and to a questionb like “Did you get your hair cut” they will answer “Yes, I got them cut”, a direct translation from French form.
BC, the West Coast, probably has the most generic of North American accents, but we have expressions that only British Columbians use, words like gonch for underwear. If I ever heard someone out east use the word gonch I would instantly know from BC. When I was working in Australia I had so many a-holes call me a dumb C Yank, “Why don’t ya f off back to America” (their mobile service disconnected). I would politely say “Actually sir, I’m Canadian, not American”. The reply was “Same f-in difference, ya dumb C”. Yes, never been called that word in my life, let alone on the telephone.
I eventually dumped my North American accent and assimilated. Australian is a very difficult one to mimic; not the country one that everyone makes fun of but a clean Oz accent. I loved not being asked if I was a tourist, or how long I was visiting for.