Beer (alcohol) production is a huge rabbit hole. Most alcohol on the planet is produced by 4 or 5 companies.
Moosehead, Original 16, and Big Rock are all (real!) Canadian beers sold in the US. Almost everything else you find will be owned by Molson-Coors, Heineken N.V.,or Anheuser-Bush InBev. That's true for ALL beer!
If you can't find the beers I mentioned, consider supporting local microbreweries. They're probably hurting pretty badly.