Accents....Canadians sound closest to americans in PNW and California.
Also North Dakota, northern Minnesota too.
Actually anywhere in western US is close to Canadian accent,
even in Arizona and most of New Mexico (except eastern NM).
Farthest from Canadian accent is anywhere in US south, from Texas to Virginia.
There are differences, not so much with accent but more with pronunciation.
Americans pronounce letter "a" in words like drama, taco, pecan
with "awe" sound. The "a" is pronounced like words saw or law.
Canadians tend to pronounce those same words with a different "a" sound,
like the "a" in words like back, sack, or crack.
Words like borrow, sorrow, all are pronounced by americans like
the first "o" is an "a". (barrow, sarrow).
Word sorry is pronounced like sarry by most americans,
Canadians over 30 pronounce it like sorey ...letter "o" not pronounce like an "a".
Interestingly younger Canadians are pronouncing sorry like USA, also the word tomorrow.(tomarrow).
Canadians pronounce words ending "ine" like turbine (same way the word sign is pronounced)
Americans pronounce words such as turbine like "turbin" (just like pin or sin).
Or words like fertile...USA it's pronounced "fertill" (like there is no "e").
No vowel shifts either, parts of US around the Great Lakes have vowel shift
where "o" is pronounced more like an "a", strongest in Chicago, noticeable as far east as Buffalo.
Gradually Canadians are pronouncing most words like americans, not exactly sure why
can't be TV as TV has been around for about 60 years.
Oh yeah, almost forgot, I do hear the difference when Canadians say "about",
sounds sort of like aboat to me. More noticeable in Ontario, much less in the west.