driver of a vehicle shall stop at a stop sign or at a clearly marked stop line before entering the intersection, https://www.revisor.mn.gov/statutes/?id=169.30

And stopping right before the stop sign is what I was taught in driver's ed, not by my grandma.

One of the joys of driving in the U.S. is every state has it's own driving laws and while they're substantially the same, they are by far not identical (see lane splitting in California vs everywhere else, and turning right on red).

Also you'll find some states will define the intersection as including sidewalks, which is why you'll usually find the stop sign placed right before the sidewalk, not after it. http://www.ncsl.org/research/transportation/pedestrian-cross...