How can a Canadian with a criminal record marry an American?
The person with the criminal record can get married to the American citizen, BUT they will NOT be granted residence in the USA. The same applies to Americans who have a criminal record, they are BARRED from entering Canada. We don't like to swap criminals.
The only alternative, and it takes a while, is to apply for a PARDON from the Canadian Government, if the conviction took place more than FIVE years ago.
The application takes about 6 months to be approved and they will do a VERY deep check on the person's life and honesty, before it is granted. The application requires a cash fee, and a finger print set done by the RCMP.