1. Legitimate companies more often do just an authorization like that rather than an actual charge. (It then shows up as "pending" on your account online, but never actually posts to a statement.)

2. They can do it for as little as a few cents. (That's what PayPal does, tho in its case its depositing, not charging, so no wonder it deposits as little as it needs to! )

3. Canadian dollars are trading within a few percent of US dollars lately, so no way would 1.00 convert to 1.21 going either way between US$ and CAN$, even if the charge had been processed with the dreadful "Dynamic Currency Conversion" (DCC). (The OP already explained their card has 0% forex, so the only way a forex charge could get on there would be if DCC was used.)

Meanwhile, the other thing to be wary of is whether it wasn't AA itself, but rather an AA spoofer. Charging small amounts like that, to see if they go through, is a known tactic of crooks getting ready to scam your account. Except usually those small charges in that case are attributed to some small company you've never heard of from someplace you've never been, rather than a major multinational you know well like AA.

(I had unexplained charges of a fraction of a dollar up to about two dollars show up a couple times in years past on a couple cards, and in each case they were fraud, but again in each case they were billed by some small company I'd never heard of in a place I'd never been to supposedly running a type of business I never use.)