There are only 7 states with more population than Sweden. Only 2 with more than Scandinavia: California and Texas.

The point of excluding inhabited ice regions is not due to lack of population its due to lack of potential developable land. My point is to put yourself in American shoes when they developed after WW2, there was so much abundance of developable land, resources, and wealth plus this new automobile coming onto the scene, it was natural that it was going to develop the way it did.