In the Americas, jaguars are counted the largest cats, and cougars the second largest. (Third and fourth worldwide, after tigers and lions.) But jaguars, which are stockier and shorter, are heaviest towards the equator, while cougars (taller and thinner) are heaviest towards the poles.
There are, apparently, no resident jaguars in the US anymore, though El Jefe, a jaguar known to hunt bears, used to stray into Arizona. (He's old, now, and doesn't wander so far. Time, maybe, for the bears to get revenge.) When we visited Oregon Cave, they said they'd found the skeleton of a prehistoric jaguar there . . .