The problem with Canada is not misdemeanors per se, their law bars the admission of those persons who have a conviction for a serious crime, which is all felonies and some misdemeanors.

The vast majority of US airline pilots don't have felonies, but where this becomes a problem is if you have a US conviction which would have been a felony crime in Canada, then they consider you to be a felon.

The crime which is the problem for 95% of of US pilots who have an issue with Canada is DUI. It is often a misdemeanor here, but is a felony in Canada.

I would check with a canadian consulate to find out if your crime is even considered a problem for entry into Canada. While they are sensitive about DUI, that might not extend to other MV violations. You can probably call and ask them without identifying yourself.

You say "long ago"? How long is that? By paying a large sum of money you can be "rehabilitated" under canadian law so that you can enter the country. In the US this process is commonly known as "extortion". There is a waiting period of five years for minor crimes, if it has been five years you could inquire with a consulate about starting that process.

If your crime makes you ineligible to enter canada, you will probably have to get rehabilitated before you can be hired by most airlines. There are a fair number of US pilots who are in this situation, however, most of them got hired BEFORE canada enacted this law post 9/11.

I don't know what records the canadians use, but I would suspect they get FBI database info or some subset of that.

Also I don't think the canadians have an issue with juvenile crimes, if you happened to be under 18.

Also AMR (the parent company of AA and AE) is known to be very hard-assed about your background. You probably need to accept full responsibility, be humble, and hope they write off the whole thing as a youthful indiscretion. If you complain that you treated unfairly by cops, legal system, etc I can GUARANTEE that you will not be hired. EVERYONE who is actually guilty complains about how they are really innocent