A bit of stretch to say they controlled that sliver of Canada; more likely they claimed it as part of the Mississippi River basin i.e. Louisiana. I doubt any Spaniard made it that far north.
Even though Spain and Portugal shared the same monarch during the Iberian Union, they were still somewhat separate independent states and Portuguese territories were administered by a council autonomous from the Habsburgs. Of course I could've included those territories, but decided not to.
Like, in what sense? I learned to create custom maps by reading the SVG guide and did research on Wikipedia and different academic sources on Spanish history.