I'd contact the Embassy over here and fess up to your previous. They can advise on what would or wouldn't constitute a current issue or restriction.
You used to be able to fill out the white and blue visa waiver form when you were on the plane but after those pesky scamps flew into the Twin Towers (allegedly) it has got a bit tighter and you now need an ESTA. These are electronic and if your deets are on any sort of Old Bill database chances are you'll come a cropper when they check you out.
I have no idea if Mexico or Canada are any more lenient but you'd look a bit chumpy trying to cross the border and get found out.
I'd fully recommend trying as America is fantastic. Shame it is full of gun toting lunatics.