Anyone wishing to enter the United States with a criminal record must apply for a U.S. entry waiver. A waiver will allow you to enter the United States hassle free. Waivers are granted on a 1 year or 5 year basis.
The Department of Homeland Security has access to the CPIC (Canadian Police Information Center ) databases. This means that they have access to your criminal record.
I am Applying for a Pardon
Individuals with a criminal record in Canada, but have never been refused entry into the US, can obtain a pardon to have their record removed before traveling.
However if the US are made aware of a past record after pardoned, entry may be refused.A Canadian Pardon is not recognized by the United States. Under the Immigration and Nationality Act of the United States.
All foreigners with a criminal record are deemed inadmissible into the United States. If the US was previously made aware of your criminal record when you crossed the border in the past, then the US has downloaded your criminal record into their systems and there is no way of getting this removed. You will have to apply for a Waiver to be able to travel into the US again.
It is up to your discretion on which application you must apply for to cross the United States border. Pardon Granted will not be held liable for any refusals at the border.