FTR, it is a pain in the butt to contact the Canadian Consulate here in the US and speak to a real person (at least the major consulate branches that handle Rehabilitation and Visas). It is better to contact the FBI and pull your own record, and then apply for a Certificate of Rehabilitation or Visa through the appropriate channels (through the Canadian Consulate or a lawyer) if need be. Warning: this will cost you! You could also apply to your governor (state crimes) or President Obama (all crimes) for a pardon, but that is a long process.

BTW, from what I know the only other country that is as strict as Canada, and who has access to the appropriate databases on Americans, is Israel. Though the UK and Australia are getting there too. Lots of other countries say you can't have a record, but have no way of checking your criminal history if you just show up to visit, such as Japan or Taiwan, unless you apply in advance for a visa.