Depends on your definition of “accent” (yes, really). Is an accent a deviation from standard/dictionary, or is standard/dictionary also an accent?
Assuming standard isn’t accent, depends on the zone/individual. We all know about Brooklyn and Southern drawl and Minnesotan, etc.
Assuming standard isn’t accent, Americans have less accent than other English-speakers, but more accent than you’d think. For example, Americans say “budder” instead of “butter”.
Americans are the ones without accents.
If you didn’t almost certainly have a gun on you right now, you’d be in for it mister.